Rework warning suppression to use global meta data

40 files changed, 607 insertions, 604 deletions

diff --git a/cpp/src/Slice/Checksum.cpp b/cpp/src/Slice/Checksum.cpp
index 1dd25cef5c8..1c8a21511e8 100644
--- a/cpp/src/Slice/Checksum.cpp
+++ b/cpp/src/Slice/Checksum.cpp
@@ -21,7 +21,7 @@ class ChecksumVisitor : public ParserVisitor
 {
 public:
 
-    ChecksumVisitor(ChecksumMap&, int);
+    ChecksumVisitor(ChecksumMap&);
 
     virtual bool visitClassDefStart(const ClassDefPtr&);
     virtual bool visitExceptionStart(const ExceptionPtr&);
@@ -41,8 +41,7 @@ private:
 
 }
 
-Slice::ChecksumVisitor::ChecksumVisitor(ChecksumMap& m, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::ChecksumVisitor::ChecksumVisitor(ChecksumMap& m) :
     _map(m)
 {
 }
@@ -442,11 +441,11 @@ Slice::ChecksumVisitor::updateMap(const string& scoped, const string& data)
 }
 
 Slice::ChecksumMap
-Slice::createChecksums(const UnitPtr& u, int warningLevel)
+Slice::createChecksums(const UnitPtr& u)
 {
     ChecksumMap result;
 
-    ChecksumVisitor visitor(result, warningLevel);
+    ChecksumVisitor visitor(result);
     u->visit(&visitor, false);
 
     return result;
diff --git a/cpp/src/Slice/Checksum.h b/cpp/src/Slice/Checksum.h
index 158ac182f77..3744d8a6ad4 100644
--- a/cpp/src/Slice/Checksum.h
+++ b/cpp/src/Slice/Checksum.h
@@ -19,7 +19,7 @@ namespace Slice
 
 typedef std::map<std::string, std::vector<unsigned char> > ChecksumMap;
 
-ChecksumMap createChecksums(const UnitPtr&, int);
+ChecksumMap createChecksums(const UnitPtr&);
 
 }
 
diff --git a/cpp/src/Slice/JavaUtil.cpp b/cpp/src/Slice/JavaUtil.cpp
index 7c2f83fb20e..461f9b7c09e 100644
--- a/cpp/src/Slice/JavaUtil.cpp
+++ b/cpp/src/Slice/JavaUtil.cpp
@@ -139,10 +139,6 @@ class MetaDataVisitor : public ParserVisitor
 {
 public:
 
-    MetaDataVisitor(int warningLevel) : ParserVisitor(warningLevel)
-    {
-    }
-
     virtual bool visitUnitStart(const UnitPtr& p)
     {
         static const string prefix = "java:";
@@ -157,6 +153,7 @@ public:
             string file = *q;
             DefinitionContextPtr dc = p->findDefinitionContext(file);
             assert(dc);
+            bool emitWarnings = !dc->suppressWarning("invalid-metadata");
             StringList globalMetaData = dc->getMetaData();
             for(StringList::const_iterator r = globalMetaData.begin(); r != globalMetaData.end();)
             {
@@ -175,7 +172,7 @@ public:
                     }
                     else
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             emitWarning(file, "",  "ignoring invalid global metadata `" + s + "'");
                         }
@@ -238,6 +235,11 @@ public:
         TypePtr returnType = p->returnType();
         StringList metaData = getMetaData(p);
 
+        UnitPtr unit = p->unit();
+        string file = p->file();
+        DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
         if(!returnType)
         {
             for(StringList::const_iterator q = metaData.begin(); q != metaData.end();)
@@ -245,7 +247,7 @@ public:
                 string s = *q++;
                 if(s.find("java:type:", 0) == 0)
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         emitWarning(p->file(), p->line(), "ignoring invalid metadata `" + s +
                                     "' for operation with void return type");
@@ -290,6 +292,10 @@ public:
 
         const string file =  p->file();
         const string line = p->line();
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(file);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
         for(StringList::const_iterator q = metaData.begin(); q != metaData.end(); )
         {
             string s = *q++;
@@ -303,7 +309,7 @@ public:
                 BuiltinPtr builtin = BuiltinPtr::dynamicCast(p->type());
                 if(!builtin || builtin->kind() != Builtin::KindByte)
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         emitWarning(file, line, "ignoring invalid metadata `" + s + "': " +
                                     "this metadata can only be used with a byte sequence");
@@ -322,7 +328,7 @@ public:
                     builtin->kind() != Builtin::KindInt && builtin->kind() != Builtin::KindLong &&
                     builtin->kind() != Builtin::KindFloat && builtin->kind() != Builtin::KindDouble))
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         emitWarning(file, line, "ignoring invalid metadata `" + s + "': " +
                                     "this metadata can not be used with this type");
@@ -372,6 +378,12 @@ private:
         StringList metaData = cont->getMetaData();
         StringList result;
 
+        UnitPtr unit = cont->container()->unit();
+        string file = cont->file();
+        DefinitionContextPtr dc = unit->findDefinitionContext(file);
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
         for(StringList::const_iterator p = metaData.begin(); p != metaData.end(); ++p)
         {
             string s = *p;
@@ -431,7 +443,7 @@ private:
                     continue;
                 }
 
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(cont->file(), cont->line(), "ignoring invalid metadata `" + s + "'");
                 }
@@ -448,6 +460,10 @@ private:
 
     StringList validateType(const SyntaxTreeBasePtr& p, const StringList& metaData, const string& file, const string& line)
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(file);
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         StringList newMetaData;
         for(StringList::const_iterator i = metaData.begin(); i != metaData.end(); ++i)
         {
@@ -468,7 +484,7 @@ private:
                     assert(b);
                     str = b->typeId();
                 }
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(file, line, "invalid metadata for " + str);
                 }
@@ -490,7 +506,7 @@ private:
 
                 }
 
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(file, line, "ignoring invalid metadata `" + *i + "'");
                 }
@@ -500,7 +516,7 @@ private:
                 //
                 // Only valid in sequence definition which is checked in visitSequence
                 //
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(file, line, "ignoring invalid metadata `" + *i + "'");
                 }
@@ -512,7 +528,7 @@ private:
                 {
                     newMetaData.push_back(*i);
                 }
-                else if(warningLevel() > 0)
+                else if(emitWarnings)
                 {
                     emitWarning(file, line, "ignoring invalid metadata `" + *i + "'");
                 }
@@ -523,7 +539,7 @@ private:
                 {
                     newMetaData.push_back(*i);
                 }
-                else if(warningLevel() > 0)
+                else if(emitWarnings)
                 {
                     emitWarning(file, line, "ignoring invalid metadata `" + *i + "'");
                 }
@@ -538,6 +554,10 @@ private:
 
     StringList validateGetSet(const SyntaxTreeBasePtr& p, const StringList& metaData, const string& file, const string& line)
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc= unit->findDefinitionContext(file);
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         StringList newMetaData;
         for(StringList::const_iterator i = metaData.begin(); i != metaData.end(); ++i)
         {
@@ -560,7 +580,7 @@ private:
                     assert(b);
                     str = b->typeId();
                 }
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(file, line, "invalid metadata for " + str);
                 }
@@ -3219,9 +3239,9 @@ Slice::JavaCompatGenerator::createOutput()
 }
 
 void
-Slice::JavaCompatGenerator::validateMetaData(const UnitPtr& u, int warningLevel)
+Slice::JavaCompatGenerator::validateMetaData(const UnitPtr& u)
 {
-    MetaDataVisitor visitor(warningLevel);
+    MetaDataVisitor visitor;
     u->visit(&visitor, true);
 }
 
@@ -5530,8 +5550,8 @@ Slice::JavaGenerator::createOutput()
 }
 
 void
-Slice::JavaGenerator::validateMetaData(const UnitPtr& u, int warningLevel)
+Slice::JavaGenerator::validateMetaData(const UnitPtr& u)
 {
-    MetaDataVisitor visitor(warningLevel);
+    MetaDataVisitor visitor;
     u->visit(&visitor, true);
 }
diff --git a/cpp/src/Slice/JavaUtil.h b/cpp/src/Slice/JavaUtil.h
index c16f78a3247..fcc77d30f63 100644
--- a/cpp/src/Slice/JavaUtil.h
+++ b/cpp/src/Slice/JavaUtil.h
@@ -68,7 +68,7 @@ public:
     //
     // Validate all metadata in the unit with a "java:" prefix.
     //
-    static void validateMetaData(const UnitPtr&, int);
+    static void validateMetaData(const UnitPtr&);
 
     void close();
 
@@ -235,7 +235,7 @@ public:
     //
     // Validate all metadata in the unit with a "java:" prefix.
     //
-    static void validateMetaData(const UnitPtr&, int);
+    static void validateMetaData(const UnitPtr&);
 
     void close();
 
diff --git a/cpp/src/Slice/Parser.cpp b/cpp/src/Slice/Parser.cpp
index 5db58db7ef9..9b95062c035 100644
--- a/cpp/src/Slice/Parser.cpp
+++ b/cpp/src/Slice/Parser.cpp
@@ -122,17 +122,6 @@ Unit* unit;
 
 }
 
-Slice::ParserVisitor::ParserVisitor(int warningLevel) : 
-    _warningLevel(warningLevel)
-{
-}
-
-int
-Slice::ParserVisitor::warningLevel()
-{
-    return _warningLevel;
-}
-
 // ----------------------------------------------------------------------
 // DefinitionContext
 // ----------------------------------------------------------------------
@@ -204,6 +193,13 @@ Slice::DefinitionContext::getMetaData() const
     return _metaData;
 }
 
+bool
+Slice::DefinitionContext::suppressWarning(const string& name) const
+{
+    string q = findMetaData("suppress-warning");
+    return q == "suppress-warning" || q == "supress-warning:all" || q == ("suppress-warning:" + name);
+}
+
 // ----------------------------------------------------------------------
 // SyntaxTreeBase
 // ----------------------------------------------------------------------
diff --git a/cpp/src/Slice/Parser.h b/cpp/src/Slice/Parser.h
index 3f969dbf330..9363105a066 100644
--- a/cpp/src/Slice/Parser.h
+++ b/cpp/src/Slice/Parser.h
@@ -191,8 +191,6 @@ class ParserVisitor
 {
 public:
 
-    ParserVisitor(int warningLevel = 1);
-
     virtual ~ParserVisitor() { }
     virtual bool visitUnitStart(const UnitPtr&) { return true; }
     virtual void visitUnitEnd(const UnitPtr&) { }
@@ -212,12 +210,6 @@ public:
     virtual void visitDictionary(const DictionaryPtr&) { }
     virtual void visitEnum(const EnumPtr&) { }
     virtual void visitConst(const ConstPtr&) { }
-
-    int warningLevel();
-
-private:
-
-    int _warningLevel;
 };
 
 // ----------------------------------------------------------------------
@@ -242,6 +234,12 @@ public:
     std::string findMetaData(const std::string&) const;
     StringList getMetaData() const;
 
+    //
+    // Check if we need to suppress the given warnings based 
+    // on the [["supress-warning"]] global meta-data
+    //
+    bool suppressWarning(const std::string& = "") const;
+
 private:
 
     int _includeLevel;
diff --git a/cpp/src/Slice/Python.cpp b/cpp/src/Slice/Python.cpp
index 057fb22cca4..bc1da962d70 100644
--- a/cpp/src/Slice/Python.cpp
+++ b/cpp/src/Slice/Python.cpp
@@ -101,13 +101,13 @@ class PackageVisitor : public ParserVisitor
 {
 public:
 
-    static void createModules(const UnitPtr&, const string&, const string&, int);
+    static void createModules(const UnitPtr&, const string&, const string&);
 
     virtual void visitModuleEnd(const ModulePtr&);
 
 private:
 
-    PackageVisitor(StringList&, int);
+    PackageVisitor(StringList&);
 
     enum ReadState { PreModules, InModules, InSubmodules };
 
@@ -128,17 +128,16 @@ private:
 const char* PackageVisitor::_moduleTag = "# Modules:";
 const char* PackageVisitor::_submoduleTag = "# Submodules:";
 
-PackageVisitor::PackageVisitor(StringList& modules, int warningLevel) :
-    ParserVisitor(warningLevel),
+PackageVisitor::PackageVisitor(StringList& modules) :
     _modules(modules)
 {
 }
 
 void
-PackageVisitor::createModules(const UnitPtr& unit, const string& module, const string& dir, int warningLevel)
+PackageVisitor::createModules(const UnitPtr& unit, const string& module, const string& dir)
 {
     StringList modules;
-    PackageVisitor v(modules, warningLevel);
+    PackageVisitor v(modules);
     unit->visit(&v, false);
 
     for(StringList::iterator p = modules.begin(); p != modules.end(); ++p)
@@ -404,7 +403,6 @@ usage(const string& n)
         "--all                Generate code for Slice definitions in included files.\n"
         "--checksum           Generate checksums for Slice definitions.\n"
         "--prefix PREFIX      Prepend filenames of Python modules with PREFIX.\n"
-        "--no-warn            Disable all warnings.\n"
         ;
 }
 
@@ -432,7 +430,6 @@ Slice::Python::compile(const vector<string>& argv)
     opts.addOpt("", "build-package");
     opts.addOpt("", "checksum");
     opts.addOpt("", "prefix", IceUtilInternal::Options::NeedArg);
-    opts.addOpt("", "no-warn");
 
     vector<string> args;
     try
@@ -503,8 +500,6 @@ Slice::Python::compile(const vector<string>& argv)
 
     string prefix = opts.optArg("prefix");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -670,7 +665,7 @@ Slice::Python::compile(const vector<string>& argv)
                             //
                             // Generate Python code.
                             //
-                            generate(u, all, checksum, includePaths, out, warningLevel);
+                            generate(u, all, checksum, includePaths, out);
 
                             out.close();
                         }
@@ -680,7 +675,7 @@ Slice::Python::compile(const vector<string>& argv)
                         //
                         if(!noPackage)
                         {
-                            PackageVisitor::createModules(u, prefix + base + "_ice", output, warningLevel);
+                            PackageVisitor::createModules(u, prefix + base + "_ice", output);
                         }
                     }
                     catch(const Slice::FileException& ex)
diff --git a/cpp/src/Slice/PythonUtil.cpp b/cpp/src/Slice/PythonUtil.cpp
index 4d5a23caf9d..9f09a765ed4 100644
--- a/cpp/src/Slice/PythonUtil.cpp
+++ b/cpp/src/Slice/PythonUtil.cpp
@@ -50,8 +50,6 @@ class MetaDataVisitor : public ParserVisitor
 {
 public:
 
-    MetaDataVisitor(int);
-
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
     virtual void visitClassDecl(const ClassDeclPtr&);
@@ -93,7 +91,7 @@ class ModuleVisitor : public ParserVisitor
 {
 public:
 
-    ModuleVisitor(Output&, set<string>&, int);
+    ModuleVisitor(Output&, set<string>&);
 
     virtual bool visitModuleStart(const ModulePtr&);
 
@@ -110,7 +108,7 @@ class CodeVisitor : public ParserVisitor
 {
 public:
 
-    CodeVisitor(IceUtilInternal::Output&, set<string>&, int);
+    CodeVisitor(IceUtilInternal::Output&, set<string>&);
 
     virtual bool visitModuleStart(const ModulePtr&);
     virtual void visitModuleEnd(const ModulePtr&);
@@ -293,8 +291,7 @@ getDictLookup(const ContainedPtr& cont, const string& suffix = "", const string&
 //
 // ModuleVisitor implementation.
 //
-Slice::Python::ModuleVisitor::ModuleVisitor(Output& out, set<string>& history, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Python::ModuleVisitor::ModuleVisitor(Output& out, set<string>& history) :
     _out(out), _history(history)
 {
 }
@@ -344,8 +341,7 @@ Slice::Python::ModuleVisitor::visitModuleStart(const ModulePtr& p)
 //
 // CodeVisitor implementation.
 //
-Slice::Python::CodeVisitor::CodeVisitor(Output& out, set<string>& moduleHistory, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Python::CodeVisitor::CodeVisitor(Output& out, set<string>& moduleHistory) :
     _out(out),
     _moduleHistory(moduleHistory)
 {
@@ -2835,9 +2831,9 @@ Slice::Python::CodeVisitor::writeDocstring(const OperationPtr& op, DocstringMode
 
 void
 Slice::Python::generate(const UnitPtr& un, bool all, bool checksum, const vector<string>& includePaths,
-                        Output& out, int warningLevel)
+                        Output& out)
 {
-    Slice::Python::MetaDataVisitor visitor(warningLevel);
+    Slice::Python::MetaDataVisitor visitor;
     un->visit(&visitor, false);
 
     out << nl << "from sys import version_info as _version_info_";
@@ -2862,15 +2858,15 @@ Slice::Python::generate(const UnitPtr& un, bool all, bool checksum, const vector
 
     set<string> moduleHistory;
 
-    ModuleVisitor moduleVisitor(out, moduleHistory, warningLevel);
+    ModuleVisitor moduleVisitor(out, moduleHistory);
     un->visit(&moduleVisitor, true);
 
-    CodeVisitor codeVisitor(out, moduleHistory, warningLevel);
+    CodeVisitor codeVisitor(out, moduleHistory);
     un->visit(&codeVisitor, false);
 
     if(checksum)
     {
-        ChecksumMap checksums = createChecksums(un, warningLevel);
+        ChecksumMap checksums = createChecksums(un);
         if(!checksums.empty())
         {
             out << sp;
@@ -2986,11 +2982,6 @@ Slice::Python::printHeader(IceUtilInternal::Output& out)
     out << "#\n";
 }
 
-Slice::Python::MetaDataVisitor::MetaDataVisitor(int warningLevel) :
-    ParserVisitor(warningLevel)
-{
-}
-
 bool
 Slice::Python::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
 {
@@ -3000,12 +2991,12 @@ Slice::Python::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
     // Validate global metadata in the top-level file and all included files.
     //
     StringList files = p->allFiles();
-
     for(StringList::iterator q = files.begin(); q != files.end(); ++q)
     {
         string file = *q;
         DefinitionContextPtr dc = p->findDefinitionContext(file);
         assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         StringList globalMetaData = dc->getMetaData();
         for(StringList::const_iterator r = globalMetaData.begin(); r != globalMetaData.end();)
         {
@@ -3018,7 +3009,7 @@ Slice::Python::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                     continue;
                 }
 
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(file, "", "ignoring invalid global metadata `" + s + "'");
                 }
@@ -3094,6 +3085,11 @@ Slice::Python::MetaDataVisitor::visitSequence(const SequencePtr& p)
     const string file = p->file();
     const string line = p->line();
     StringList protobufMetaData;
+    const UnitPtr unit = p->unit();
+    const DefinitionContextPtr dc = unit->findDefinitionContext(file);
+    assert(dc);
+    bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
     for(StringList::const_iterator q = metaData.begin(); q != metaData.end(); )
     {
         string s = *q++;
@@ -3106,7 +3102,7 @@ Slice::Python::MetaDataVisitor::visitSequence(const SequencePtr& p)
             BuiltinPtr builtin = BuiltinPtr::dynamicCast(p->type());
             if(!builtin || builtin->kind() != Builtin::KindByte)
             {
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     emitWarning(file, line, "ignoring invalid metadata `" + s + ": " +
                                 "`protobuf' encoding must be a byte sequence");
@@ -3146,6 +3142,11 @@ StringList
 Slice::Python::MetaDataVisitor::validateSequence(const string& file, const string& line,
                                                  const TypePtr& type, const StringList& metaData)
 {
+    const UnitPtr unit = type->unit();
+    const DefinitionContextPtr dc = unit->findDefinitionContext(file);
+    assert(dc);
+    bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
     static const string prefix = "python:";
     StringList newMetaData = metaData;
     for(StringList::const_iterator p = newMetaData.begin(); p != newMetaData.end();)
@@ -3166,7 +3167,7 @@ Slice::Python::MetaDataVisitor::validateSequence(const string& file, const strin
                     }
                 }
             }
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 emitWarning(file, line, "ignoring invalid metadata `" + s + "'");
             }
@@ -3181,12 +3182,21 @@ Slice::Python::MetaDataVisitor::reject(const ContainedPtr& cont)
 {
     StringList localMetaData = cont->getMetaData();
     static const string prefix = "python:";
+
+    const UnitPtr unit = cont->unit();
+    const DefinitionContextPtr dc = unit->findDefinitionContext(cont->file());
+    assert(dc);
+    bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
     for(StringList::const_iterator p = localMetaData.begin(); p != localMetaData.end();)
     {
         string s = *p++;
         if(s.find(prefix) == 0)
         {
-            emitWarning(cont->file(), cont->line(), "ignoring invalid metadata `" + s + "'");
+            if(emitWarnings)
+            {
+                emitWarning(cont->file(), cont->line(), "ignoring invalid metadata `" + s + "'");
+            }
             localMetaData.remove(s);
         }
     }
diff --git a/cpp/src/Slice/PythonUtil.h b/cpp/src/Slice/PythonUtil.h
index 161d3bdb148..9d48b3d3871 100644
--- a/cpp/src/Slice/PythonUtil.h
+++ b/cpp/src/Slice/PythonUtil.h
@@ -21,7 +21,7 @@ namespace Python
 //
 // Generate Python code for a translation unit.
 //
-void generate(const Slice::UnitPtr&, bool, bool, const std::vector<std::string>&, IceUtilInternal::Output&, int);
+void generate(const Slice::UnitPtr&, bool, bool, const std::vector<std::string>&, IceUtilInternal::Output&);
 
 //
 // Convert a scoped name into a Python name.
diff --git a/cpp/src/Slice/Ruby.cpp b/cpp/src/Slice/Ruby.cpp
index 7bd4dd07d17..7861bcb8c0b 100644
--- a/cpp/src/Slice/Ruby.cpp
+++ b/cpp/src/Slice/Ruby.cpp
@@ -81,7 +81,6 @@ usage(const string& n)
         "                     deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore         Allow underscores in Slice identifiers\n"
         "                     deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn            Disable all warnings.\n"
         ;
 }
 
@@ -106,7 +105,6 @@ Slice::Ruby::compile(const vector<string>& argv)
     opts.addOpt("", "underscore");
     opts.addOpt("", "all");
     opts.addOpt("", "checksum");
-    opts.addOpt("", "no-warn");
 
     vector<string> args;
     try
@@ -171,8 +169,6 @@ Slice::Ruby::compile(const vector<string>& argv)
 
     bool checksum = opts.isSet("checksum");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -315,7 +311,7 @@ Slice::Ruby::compile(const vector<string>& argv)
                         //
                         // Generate the Ruby mapping.
                         //
-                        generate(u, all, checksum, includePaths, out, warningLevel);
+                        generate(u, all, checksum, includePaths, out);
 
                         out.close();
                     }
diff --git a/cpp/src/Slice/RubyUtil.cpp b/cpp/src/Slice/RubyUtil.cpp
index 574a7cf2644..9c1a32d8e77 100644
--- a/cpp/src/Slice/RubyUtil.cpp
+++ b/cpp/src/Slice/RubyUtil.cpp
@@ -52,7 +52,7 @@ class CodeVisitor : public ParserVisitor
 {
 public:
 
-    CodeVisitor(IceUtilInternal::Output&, int);
+    CodeVisitor(IceUtilInternal::Output&);
 
     virtual bool visitModuleStart(const ModulePtr&);
     virtual void visitModuleEnd(const ModulePtr&);
@@ -184,8 +184,7 @@ splitScopedName(const string& scoped)
 //
 // CodeVisitor implementation.
 //
-Slice::Ruby::CodeVisitor::CodeVisitor(Output& out, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Ruby::CodeVisitor::CodeVisitor(Output& out) :
     _out(out)
 {
 }
@@ -1446,8 +1445,7 @@ Slice::Ruby::CodeVisitor::collectExceptionMembers(const ExceptionPtr& p, MemberI
 }
 
 void
-Slice::Ruby::generate(const UnitPtr& un, bool all, bool checksum, const vector<string>& includePaths, Output& out, 
-                      int warningLevel)
+Slice::Ruby::generate(const UnitPtr& un, bool all, bool checksum, const vector<string>& includePaths, Output& out)
 {
     out << nl << "require 'Ice'";
 
@@ -1467,12 +1465,12 @@ Slice::Ruby::generate(const UnitPtr& un, bool all, bool checksum, const vector<s
         }
     }
 
-    CodeVisitor codeVisitor(out, warningLevel);
+    CodeVisitor codeVisitor(out);
     un->visit(&codeVisitor, false);
 
     if(checksum)
     {
-        ChecksumMap checksums = createChecksums(un, warningLevel);
+        ChecksumMap checksums = createChecksums(un);
         if(!checksums.empty())
         {
             out << sp;
diff --git a/cpp/src/Slice/RubyUtil.h b/cpp/src/Slice/RubyUtil.h
index 387cbc67073..e67ecd1b623 100644
--- a/cpp/src/Slice/RubyUtil.h
+++ b/cpp/src/Slice/RubyUtil.h
@@ -21,7 +21,7 @@ namespace Ruby
 //
 // Generate Ruby code for a translation unit.
 //
-void generate(const Slice::UnitPtr&, bool, bool, const std::vector<std::string>&, IceUtilInternal::Output&, int);
+void generate(const Slice::UnitPtr&, bool, bool, const std::vector<std::string>&, IceUtilInternal::Output&);
 
 //
 // Check the given identifier against Ruby's list of reserved words. If it matches
diff --git a/cpp/src/slice2confluence/Gen.cpp b/cpp/src/slice2confluence/Gen.cpp
index 77624f6cdfa..678ab4bfda6 100644
--- a/cpp/src/slice2confluence/Gen.cpp
+++ b/cpp/src/slice2confluence/Gen.cpp
@@ -39,8 +39,7 @@ namespace Slice
 void
 generate(const UnitPtr& unit, const string& dir, const string& header, const string& footer,
          const string& indexHeader, const string& indexFooter, const string& imageDir, const string& logoURL,
-         const string& searchAction, unsigned indexCount, unsigned warnSummary, const vector<string>& sortOrder,
-         int warningLevel)
+         const string& searchAction, unsigned indexCount, unsigned warnSummary, const vector<string>& sortOrder)
 {
     unit->mergeModules();
 
@@ -69,19 +68,19 @@ generate(const UnitPtr& unit, const string& dir, const string& header, const str
     // to the symbol; if the latter, we cannot.
     //
     Files files;
-    FileVisitor tv(files, warningLevel);
+    FileVisitor tv(files);
     unit->visit(&tv, false);
 
     //
     // Generate the start page.
     //
-    StartPageVisitor spv(files, warningLevel);
+    StartPageVisitor spv(files);
     unit->visit(&spv, false);
 
     //
     // Generate the table of contents.
     //
-    TOCVisitor tocv(files, indexHeader, indexFooter, warningLevel);
+    TOCVisitor tocv(files, indexHeader, indexFooter);
     unit->visit(&tocv, false);
     tocv.generate();
 
@@ -89,7 +88,7 @@ generate(const UnitPtr& unit, const string& dir, const string& header, const str
     // Generate the individual HTML pages.
     //
     GeneratorBase::setSymbols(tocv.symbols());
-    PageVisitor v(files, warningLevel);
+    PageVisitor v(files);
     unit->visit(&v, false);
 }
 
@@ -1954,8 +1953,7 @@ Slice::StartPageGenerator::printHeaderFooter()
     // Do nothing
 }
 
-Slice::FileVisitor::FileVisitor(Files& files, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::FileVisitor::FileVisitor(Files& files) :
     _files(files)
 {
 }
@@ -2018,8 +2016,7 @@ Slice::FileVisitor::visitEnum(const EnumPtr& e)
     _files.insert(e->file());
 }
 
-Slice::StartPageVisitor::StartPageVisitor(const Files& files, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::StartPageVisitor::StartPageVisitor(const Files& files) :
     _spg(files)
 {
 }
@@ -2176,8 +2173,7 @@ TOCGenerator::writeEntry(const ContainedPtr& c)
     end();
 }
 
-TOCVisitor::TOCVisitor(const Files& files, const string& header, const string& footer, int warningLevel) :
-    ParserVisitor(warningLevel),
+TOCVisitor::TOCVisitor(const Files& files, const string& header, const string& footer) :
     _tg(files, header, footer)
 {
 }
@@ -3267,8 +3263,7 @@ Slice::EnumGenerator::generate(const EnumPtr& e)
     assert(_out.currIndent() == indent);
 }
 
-Slice::PageVisitor::PageVisitor(const Files& files, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::PageVisitor::PageVisitor(const Files& files) :
     _files(files)
 {
 }
diff --git a/cpp/src/slice2confluence/Gen.h b/cpp/src/slice2confluence/Gen.h
index 587e28c7d1e..bc10790604b 100644
--- a/cpp/src/slice2confluence/Gen.h
+++ b/cpp/src/slice2confluence/Gen.h
@@ -21,7 +21,7 @@ namespace Slice
 
 void generate(const UnitPtr&, const ::std::string&, const ::std::string&, const ::std::string&, const std::string&,
               const ::std::string&, const ::std::string&, const ::std::string&, const ::std::string&,
-              unsigned, unsigned, const ::std::vector<std::string>& = ::std::vector<std::string>(), int = 1);
+              unsigned, unsigned, const ::std::vector<std::string>& = ::std::vector<std::string>());
     
 typedef ::std::set< ::std::string> Files;
 
@@ -165,7 +165,7 @@ class FileVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    FileVisitor(Files&, int);
+    FileVisitor(Files&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
@@ -186,7 +186,7 @@ class StartPageVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    StartPageVisitor(const Files&, int);
+    StartPageVisitor(const Files&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
@@ -219,7 +219,7 @@ class TOCVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    TOCVisitor(const Files&, const ::std::string&, const ::std::string&, int);
+    TOCVisitor(const Files&, const ::std::string&, const ::std::string&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
@@ -279,7 +279,7 @@ class PageVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    PageVisitor(const Files&, int);
+    PageVisitor(const Files&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
diff --git a/cpp/src/slice2confluence/Main.cpp b/cpp/src/slice2confluence/Main.cpp
index 38c7d5e2319..8eeca1c303b 100644
--- a/cpp/src/slice2confluence/Main.cpp
+++ b/cpp/src/slice2confluence/Main.cpp
@@ -108,7 +108,6 @@ usage(const string& n)
         "                     deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore         Allow underscores in Slice identifiers\n"
         "                     deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn            Disable all warnings.\n"
         ;
 }
 
@@ -137,7 +136,6 @@ compile(const vector<string>& argv)
     opts.addOpt("d", "debug");
     opts.addOpt("", "ice");
     opts.addOpt("", "underscore");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
     vector<string> args;
@@ -250,8 +248,6 @@ compile(const vector<string>& argv)
 
     bool underscore = opts.isSet("underscore");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -322,7 +318,7 @@ compile(const vector<string>& argv)
         try
         {
             Slice::generate(p, output, header, footer, indexHeader, indexFooter, imageDir, logoURL,
-                            searchAction, indexCount, summaryCount, sort_order, warningLevel);
+                            searchAction, indexCount, summaryCount, sort_order);
         }
         catch(const Slice::FileException& ex)
         {
diff --git a/cpp/src/slice2cpp/Gen.cpp b/cpp/src/slice2cpp/Gen.cpp
index dd1ca22855c..beae822ec6b 100644
--- a/cpp/src/slice2cpp/Gen.cpp
+++ b/cpp/src/slice2cpp/Gen.cpp
@@ -377,7 +377,7 @@ condString(bool ok, const string& str)
 Slice::Gen::Gen(const string& base, const string& headerExtension, const string& sourceExtension,
                 const vector<string>& extraHeaders, const string& include,
                 const vector<string>& includePaths, const string& dllExport, const string& dir,
-                bool implCpp98, bool implCpp11, bool checksum, bool ice, int warningLevel) :
+                bool implCpp98, bool implCpp11, bool checksum, bool ice) :
     _base(base),
     _headerExtension(headerExtension),
     _implHeaderExtension(headerExtension),
@@ -390,8 +390,7 @@ Slice::Gen::Gen(const string& base, const string& headerExtension, const string&
     _implCpp98(implCpp98),
     _implCpp11(implCpp11),
     _checksum(checksum),
-    _ice(ice),
-    _warningLevel(warningLevel)
+    _ice(ice)
 {
     for(vector<string>::iterator p = _includePaths.begin(); p != _includePaths.end(); ++p)
     {
@@ -423,7 +422,7 @@ Slice::Gen::generateChecksumMap(const UnitPtr& p)
 {
     if(_checksum)
     {
-        ChecksumMap map = createChecksums(p, _warningLevel);
+        ChecksumMap map = createChecksums(p);
         if(!map.empty())
         {
             C << sp << nl << "namespace";
@@ -456,13 +455,19 @@ Slice::Gen::generate(const UnitPtr& p)
     string file = p->topLevelFile();
 
     //
-    // Give precedence to header-ext global metadata.
+    // Give precedence to header-ext/source-ext global metadata.
     //
     string headerExtension = getHeaderExt(file, p);
     if(!headerExtension.empty())
     {
         _headerExtension = headerExtension;
     }
+    
+    string sourceExtension = getSourceExt(file, p);
+    if(!sourceExtension.empty())
+    {
+        _sourceExtension = sourceExtension;
+    }
 
     //
     // Give precedence to --dll-export command-line option
@@ -574,7 +579,7 @@ Slice::Gen::generate(const UnitPtr& p)
     H << "\n#define __" << s << "__";
     H << '\n';
 
-    validateMetaData(p, _warningLevel);
+    validateMetaData(p);
 
     writeExtraHeaders(C);
 
@@ -685,15 +690,30 @@ Slice::Gen::generate(const UnitPtr& p)
         DefinitionContextPtr dc = p->findDefinitionContext(file);
         assert(dc);
         StringList globalMetaData = dc->getMetaData();
-        for(StringList::const_iterator q = globalMetaData.begin(); q != globalMetaData.end(); ++q)
+        bool emitWarnings = dc->suppressWarning("invalid-metadata");
+        for(StringList::const_iterator q = globalMetaData.begin(); q != globalMetaData.end();)
         {
-            string s = *q;
+            string s = *q++;
             static const string includePrefix = "cpp:include:";
-            if(s.find(includePrefix) == 0 && s.size() > includePrefix.size())
+            if(s.find(includePrefix) == 0)
             {
-                H << nl << "#include <" << s.substr(includePrefix.size()) << ">";
+                if(s.size() > includePrefix.size())
+                {
+                    H << nl << "#include <" << s.substr(includePrefix.size()) << ">";
+                }
+                else
+                {
+                    if(emitWarnings)
+                    {
+                        ostringstream ostr;
+                        ostr << "ignoring invalid global metadata `" << s << "'";
+                        emitWarning(file, -1, ostr.str());
+                    }
+                    globalMetaData.remove(s);
+                }
             }
         }
+        dc->setMetaData(globalMetaData);
     }
 
     //
@@ -728,27 +748,27 @@ Slice::Gen::generate(const UnitPtr& p)
     C << nl << "#ifdef ICE_CPP11_MAPPING // C++11 mapping";
     C.restoreIndent();
     {
-        normalizeMetaData(p, true, _warningLevel);
+        normalizeMetaData(p, true);
 
-        Cpp11DeclVisitor declVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11DeclVisitor declVisitor(H, C, _dllExport);
         p->visit(&declVisitor, false);
 
-        Cpp11TypesVisitor typesVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11TypesVisitor typesVisitor(H, C, _dllExport);
         p->visit(&typesVisitor, false);
 
-        Cpp11LocalObjectVisitor localObjectVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11LocalObjectVisitor localObjectVisitor(H, C, _dllExport);
         p->visit(&localObjectVisitor, false);
 
-        Cpp11InterfaceVisitor interfaceVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11InterfaceVisitor interfaceVisitor(H, C, _dllExport);
         p->visit(&interfaceVisitor, false);
 
-        Cpp11ValueVisitor valueVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11ValueVisitor valueVisitor(H, C, _dllExport);
         p->visit(&valueVisitor, false);
 
-        Cpp11ProxyVisitor proxyVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11ProxyVisitor proxyVisitor(H, C, _dllExport);
         p->visit(&proxyVisitor, false);
 
-        Cpp11StreamVisitor streamVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11StreamVisitor streamVisitor(H, C, _dllExport);
         p->visit(&streamVisitor, false);
 
         if(_implCpp11)
@@ -769,11 +789,11 @@ Slice::Gen::generate(const UnitPtr& p)
             }
             implC << _base << "I." << _implHeaderExtension << ">";
 
-            Cpp11ImplVisitor implVisitor(implH, implC, _dllExport, _warningLevel);
+            Cpp11ImplVisitor implVisitor(implH, implC, _dllExport);
             p->visit(&implVisitor, false);
         }
 
-        Cpp11CompatibilityVisitor compatibilityVisitor(H, C, _dllExport, _warningLevel);
+        Cpp11CompatibilityVisitor compatibilityVisitor(H, C, _dllExport);
         p->visit(&compatibilityVisitor, false);
 
         generateChecksumMap(p);
@@ -788,21 +808,21 @@ Slice::Gen::generate(const UnitPtr& p)
     C << nl << "#else // C++98 mapping";
     C.restoreIndent();
     {
-        normalizeMetaData(p, false, _warningLevel);
+        normalizeMetaData(p, false);
 
-        ProxyDeclVisitor proxyDeclVisitor(H, C, _dllExport, _warningLevel);
+        ProxyDeclVisitor proxyDeclVisitor(H, C, _dllExport);
         p->visit(&proxyDeclVisitor, false);
 
-        ObjectDeclVisitor objectDeclVisitor(H, C, _dllExport, _warningLevel);
+        ObjectDeclVisitor objectDeclVisitor(H, C, _dllExport);
         p->visit(&objectDeclVisitor, false);
 
-        TypesVisitor typesVisitor(H, C, _dllExport, _warningLevel);
+        TypesVisitor typesVisitor(H, C, _dllExport);
         p->visit(&typesVisitor, false);
 
-        AsyncVisitor asyncVisitor(H, C, _dllExport, _warningLevel);
+        AsyncVisitor asyncVisitor(H, C, _dllExport);
         p->visit(&asyncVisitor, false);
 
-        AsyncImplVisitor asyncImplVisitor(H, C, _dllExport, _warningLevel);
+        AsyncImplVisitor asyncImplVisitor(H, C, _dllExport);
         p->visit(&asyncImplVisitor, false);
 
         //
@@ -811,16 +831,16 @@ Slice::Gen::generate(const UnitPtr& p)
         // the proxy relies on knowing the hierarchy to make the begin_
         // methods type-safe.
         //
-        AsyncCallbackVisitor asyncCallbackVisitor(H, C, _dllExport, _warningLevel);
+        AsyncCallbackVisitor asyncCallbackVisitor(H, C, _dllExport);
         p->visit(&asyncCallbackVisitor, false);
 
-        ProxyVisitor proxyVisitor(H, C, _dllExport, _warningLevel);
+        ProxyVisitor proxyVisitor(H, C, _dllExport);
         p->visit(&proxyVisitor, false);
 
-        ObjectVisitor objectVisitor(H, C, _dllExport, _warningLevel);
+        ObjectVisitor objectVisitor(H, C, _dllExport);
         p->visit(&objectVisitor, false);
 
-        StreamVisitor streamVisitor(H, C, _dllExport, _warningLevel);
+        StreamVisitor streamVisitor(H, C, _dllExport);
         p->visit(&streamVisitor, false);
 
         //
@@ -828,7 +848,7 @@ Slice::Gen::generate(const UnitPtr& p)
         // definition, because completed calls the begin_ method in the
         // proxy.
         //
-        AsyncCallbackTemplateVisitor asyncCallbackTemplateVisitor(H, C, _dllExport, _warningLevel);
+        AsyncCallbackTemplateVisitor asyncCallbackTemplateVisitor(H, C, _dllExport);
         p->visit(&asyncCallbackTemplateVisitor, false);
 
         if(_implCpp98)
@@ -849,7 +869,7 @@ Slice::Gen::generate(const UnitPtr& p)
             }
             implC << _base << "I." << _implHeaderExtension << ">";
 
-            ImplVisitor implVisitor(implH, implC, _dllExport, _warningLevel);
+            ImplVisitor implVisitor(implH, implC, _dllExport);
             p->visit(&implVisitor, false);
         }
 
@@ -903,8 +923,7 @@ Slice::Gen::writeExtraHeaders(IceUtilInternal::Output& out)
     }
 }
 
-Slice::Gen::TypesVisitor::TypesVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::TypesVisitor::TypesVisitor(Output& h, Output& c, const string& dllExport) :
     H(h), C(c), _dllExport(dllExport), _doneStaticSymbol(false), _useWstring(false)
 {
 }
@@ -1538,8 +1557,7 @@ Slice::Gen::TypesVisitor::emitUpcall(const ExceptionPtr& base, const string& cal
       << call;
 }
 
-Slice::Gen::ProxyDeclVisitor::ProxyDeclVisitor(Output& h, Output&, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::ProxyDeclVisitor::ProxyDeclVisitor(Output& h, Output&, const string& dllExport) :
     H(h), _dllExport(dllExport)
 {
 }
@@ -1606,8 +1624,8 @@ Slice::Gen::ProxyDeclVisitor::visitClassDecl(const ClassDeclPtr& p)
     H << nl << _dllExport << "::IceProxy::Ice::Object* upCast(::IceProxy" << scoped << "*);";
 }
 
-Slice::Gen::ProxyVisitor::ProxyVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport), _dllClassExport(toDllClassExport(dllExport)),
+Slice::Gen::ProxyVisitor::ProxyVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport), _dllClassExport(toDllClassExport(dllExport)),
     _dllMemberExport(toDllMemberExport(dllExport)), _useWstring(false)
 {
 }
@@ -2156,8 +2174,7 @@ Slice::Gen::ProxyVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::ObjectDeclVisitor::ObjectDeclVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::ObjectDeclVisitor::ObjectDeclVisitor(Output& h, Output& c, const string& dllExport) :
     H(h), C(c), _dllExport(dllExport)
 {
 }
@@ -2226,8 +2243,7 @@ Slice::Gen::ObjectDeclVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::ObjectVisitor::ObjectVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::ObjectVisitor::ObjectVisitor(Output& h, Output& c, const string& dllExport) :
     H(h), C(c), _dllExport(dllExport), _doneStaticSymbol(false), _useWstring(false)
 {
 }
@@ -3387,8 +3403,7 @@ Slice::Gen::ObjectVisitor::emitUpcall(const ClassDefPtr& base, const string& cal
     C << nl << (base ? fixKwd(base->scoped()) : string("::Ice::Object")) << call;
 }
 
-Slice::Gen::AsyncCallbackVisitor::AsyncCallbackVisitor(Output& h, Output&, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::AsyncCallbackVisitor::AsyncCallbackVisitor(Output& h, Output&, const string& dllExport) :
     H(h), _dllExport(dllExport), _useWstring(false)
 {
 }
@@ -3447,8 +3462,8 @@ Slice::Gen::AsyncCallbackVisitor::visitOperation(const OperationPtr& p)
     H << nl << "typedef ::IceUtil::Handle< " << delName << "_Base> " << delName << "Ptr;";
 }
 
-Slice::Gen::AsyncCallbackTemplateVisitor::AsyncCallbackTemplateVisitor(Output& h, Output&, const string& dllExport, int warningLevel)
-    : ParserVisitor(warningLevel), H(h), _dllExport(dllExport), _useWstring(false)
+Slice::Gen::AsyncCallbackTemplateVisitor::AsyncCallbackTemplateVisitor(Output& h, Output&, const string& dllExport)
+    : H(h), _dllExport(dllExport), _useWstring(false)
 {
 }
 
@@ -3751,8 +3766,8 @@ Slice::Gen::AsyncCallbackTemplateVisitor::generateOperation(const OperationPtr&
     }
 }
 
-Slice::Gen::ImplVisitor::ImplVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport), _useWstring(false)
+Slice::Gen::ImplVisitor::ImplVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport), _useWstring(false)
 {
 }
 
@@ -4043,8 +4058,8 @@ Slice::Gen::ImplVisitor::visitClassDefStart(const ClassDefPtr& p)
     return true;
 }
 
-Slice::Gen::AsyncVisitor::AsyncVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport), _useWstring(false)
+Slice::Gen::AsyncVisitor::AsyncVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport), _useWstring(false)
 {
 }
 
@@ -4178,8 +4193,8 @@ Slice::Gen::AsyncVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::AsyncImplVisitor::AsyncImplVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport), _useWstring(false)
+Slice::Gen::AsyncImplVisitor::AsyncImplVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport), _useWstring(false)
 {
 }
 
@@ -4343,8 +4358,7 @@ Slice::Gen::AsyncImplVisitor::visitOperation(const OperationPtr& p)
     C << eb;
 }
 
-Slice::Gen::StreamVisitor::StreamVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::StreamVisitor::StreamVisitor(Output& h, Output& c, const string& dllExport) :
     H(h),
     C(c),
     _dllExport(dllExport)
@@ -4475,16 +4489,12 @@ Slice::Gen::StreamVisitor::visitEnum(const EnumPtr& p)
 }
 
 void
-Slice::Gen::validateMetaData(const UnitPtr& u, int warningLevel)
+Slice::Gen::validateMetaData(const UnitPtr& u)
 {
-    MetaDataVisitor visitor(warningLevel);
+    MetaDataVisitor visitor;
     u->visit(&visitor, false);
 }
 
-Slice::Gen::MetaDataVisitor::MetaDataVisitor(int warningLevel) : ParserVisitor(warningLevel)
-{
-}
-
 bool
 Slice::Gen::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
 {
@@ -4502,22 +4512,22 @@ Slice::Gen::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
         DefinitionContextPtr dc = p->findDefinitionContext(file);
         assert(dc);
         StringList globalMetaData = dc->getMetaData();
-        StringList newGlobalMetaData;
         int headerExtension = 0;
+        int sourceExtension = 0;
         int dllExport = 0;
-        for(StringList::const_iterator r = globalMetaData.begin(); r != globalMetaData.end(); ++r)
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+        for(StringList::const_iterator r = globalMetaData.begin(); r != globalMetaData.end();)
         {
-            string s = *r;
-
+            string s = *r++;
             if(s.find(prefix) == 0)
             {
                 static const string cppIncludePrefix = "cpp:include:";
                 static const string cppHeaderExtPrefix = "cpp:header-ext:";
+                static const string cppSourceExtPrefix = "cpp:source-ext:";
                 static const string cppDllExportPrefix = "cpp:dll-export:";
 
                 if(s.find(cppIncludePrefix) == 0 && s.size() > cppIncludePrefix.size())
                 {
-                    newGlobalMetaData.push_back(s);
                     continue;
                 }
                 else if(s.find(cppHeaderExtPrefix) == 0 && s.size() > cppHeaderExtPrefix.size())
@@ -4525,17 +4535,30 @@ Slice::Gen::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                     headerExtension++;
                     if(headerExtension > 1)
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             ostringstream ostr;
                             ostr << "ignoring invalid global metadata `" << s
                                 << "': directive can appear only once per file";
                             emitWarning(file, -1, ostr.str());
                         }
+                        globalMetaData.remove(s);
                     }
-                    else
+                    continue;
+                }
+                else if(s.find(cppSourceExtPrefix) == 0 && s.size() > cppSourceExtPrefix.size())
+                {
+                    sourceExtension++;
+                    if(sourceExtension > 1)
                     {
-                        newGlobalMetaData.push_back(s);
+                        if(emitWarnings)
+                        {
+                            ostringstream ostr;
+                            ostr << "ignoring invalid global metadata `" << s
+                                << "': directive can appear only once per file";
+                            emitWarning(file, -1, ostr.str());
+                        }
+                        globalMetaData.remove(s);
                     }
                     continue;
                 }
@@ -4544,31 +4567,29 @@ Slice::Gen::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                     dllExport++;
                     if(dllExport > 1)
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             ostringstream ostr;
                             ostr << "ignoring invalid global metadata `" << s
                                 << "': directive can appear only once per file";
                             emitWarning(file, -1, ostr.str());
                         }
-                    }
-                    else
-                    {
-                        newGlobalMetaData.push_back(s);
+                        globalMetaData.remove(s);
                     }
                     continue;
                 }
 
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     ostringstream ostr;
                     ostr << "ignoring invalid global metadata `" << s << "'";
                     emitWarning(file, -1, ostr.str());
                 }
+                globalMetaData.remove(s);
             }
 
         }
-        dc->setMetaData(newGlobalMetaData);
+        dc->setMetaData(globalMetaData);
     }
 
     return true;
@@ -4640,9 +4661,14 @@ Slice::Gen::MetaDataVisitor::visitOperation(const OperationPtr& p)
 
     StringList metaData = p->getMetaData();
 
+    const UnitPtr unit = p->unit();
+    const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+    assert(dc);
+    bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
     if(!cl->isLocal() && p->hasMetaData("cpp:noexcept"))
     {
-        if(warningLevel() > 0)
+        if(emitWarnings)
         {
             emitWarning(p->file(), p->line(), "ignoring metadata `cpp:noexcept' for non local interface");
         }
@@ -4654,18 +4680,18 @@ Slice::Gen::MetaDataVisitor::visitOperation(const OperationPtr& p)
     {
         for(StringList::const_iterator q = metaData.begin(); q != metaData.end();)
         {
-            if(q->find("cpp:type:") == 0 || q->find("cpp:view-type:") == 0 ||
-               q->find("cpp:range") == 0 || (*q) == "cpp:array")
+            string s = *q++;
+            if(s.find("cpp:type:") == 0 || s.find("cpp:view-type:") == 0 ||
+               s.find("cpp:range") == 0 || s == "cpp:array")
             {
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
-                    emitWarning(p->file(), p->line(), "ignoring invalid metadata `" + *q +
+                    emitWarning(p->file(), p->line(), "ignoring invalid metadata `" + s +
                                 "' for operation with void return type");
                 }
-                metaData.remove(*q);
+                metaData.remove(s);
                 continue;
             }
-            ++q;
         }
     }
     else
@@ -4726,10 +4752,15 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
     static const string cpp11Prefix = "cpp11:";
     static const string cpp98Prefix  = "cpp98:";
 
-    StringList newMetaData;
-    for(StringList::const_iterator p = metaData.begin(); p != metaData.end(); ++p)
+    const UnitPtr unit = cont->unit();
+    const DefinitionContextPtr dc = unit->findDefinitionContext(file);
+    assert(dc);
+    bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
+    StringList newMetaData = metaData;
+    for(StringList::const_iterator p = newMetaData.begin(); p != newMetaData.end();)
     {
-        string s = *p;
+        string s = *p++;
 
         string prefix;
         bool cpp98 = false;
@@ -4752,7 +4783,6 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
 
         if(s == "cpp:const" && operation)
         {
-            newMetaData.push_back(s);
             continue;
         }
         if(!prefix.empty())
@@ -4767,7 +4797,6 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
                 ExceptionPtr exception = ExceptionPtr::dynamicCast(cont);
                 if((builtin && builtin->kind() == Builtin::KindString) || module || clss || strct || exception)
                 {
-                    newMetaData.push_back(s);
                     continue;
                 }
             }
@@ -4775,7 +4804,6 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
             {
                 if(BuiltinPtr::dynamicCast(cont)->kind() == Builtin::KindString)
                 {
-                    newMetaData.push_back(s);
                     continue;
                 }
             }
@@ -4783,18 +4811,15 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
             {
                 if(ss.find("type:") == 0 || ss.find("view-type:") == 0 || ss == "array" || ss.find("range") == 0)
                 {
-                    newMetaData.push_back(s);
                     continue;
                 }
             }
             if(DictionaryPtr::dynamicCast(cont) && (ss.find("type:") == 0 || ss.find("view-type:") == 0))
             {
-                newMetaData.push_back(s);
                 continue;
             }
             if(!cpp11 && StructPtr::dynamicCast(cont) && (ss == "class" || ss == "comparable"))
             {
-                newMetaData.push_back(s);
                 continue;
             }
 
@@ -4804,18 +4829,15 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
                           (cl->isLocal() && ss.find("type:") == 0) ||
                           (!cpp11 && cl->isLocal() && ss == "comparable")))
                 {
-                    newMetaData.push_back(s);
                     continue;
                 }
             }
             if(ExceptionPtr::dynamicCast(cont) && ss == "ice_print")
             {
-                newMetaData.push_back(s);
                 continue;
             }
             if(!cpp98 && EnumPtr::dynamicCast(cont) && ss == "unscoped")
             {
-                newMetaData.push_back(s);
                 continue;
             }
 
@@ -4823,15 +4845,15 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
                 ClassDeclPtr cl = ClassDeclPtr::dynamicCast(cont);
                 if(cl && cl->isLocal() && ss.find("type:") == 0)
                 {
-                    newMetaData.push_back(s);
                     continue;
                 }
             }
 
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 emitWarning(file, line, "ignoring invalid metadata `" + s + "'");
             }
+            newMetaData.remove(s);
             continue;
         }
 
@@ -4840,31 +4862,29 @@ Slice::Gen::MetaDataVisitor::validate(const SyntaxTreeBasePtr& cont, const Strin
             ClassDefPtr cl = ClassDefPtr::dynamicCast(cont);
             if(cl && cl->isDelegate())
             {
-                newMetaData.push_back(s);
                 continue;
             }
 
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 emitWarning(file, line, "ignoring invalid metadata `" + s + "'");
             }
+            newMetaData.remove(s);
             continue;
         }
-        newMetaData.push_back(s);
     }
     return newMetaData;
 }
 
 
 void
-Slice::Gen::normalizeMetaData(const UnitPtr& u, bool cpp11, int warningLevel)
+Slice::Gen::normalizeMetaData(const UnitPtr& u, bool cpp11)
 {
-    NormalizeMetaDataVisitor visitor(cpp11, warningLevel);
+    NormalizeMetaDataVisitor visitor(cpp11);
     u->visit(&visitor, false);
 }
 
-Slice::Gen::NormalizeMetaDataVisitor::NormalizeMetaDataVisitor(bool cpp11, int warningLevel) :
-	ParserVisitor(warningLevel),
+Slice::Gen::NormalizeMetaDataVisitor::NormalizeMetaDataVisitor(bool cpp11) :
     _cpp11(cpp11)
 {
 }
@@ -5138,9 +5158,24 @@ Slice::Gen::getHeaderExt(const string& file, const UnitPtr& unit)
     return ext;
 }
 
+string
+Slice::Gen::getSourceExt(const string& file, const UnitPtr& unit)
+{
+    string ext;
+    static const string sourceExtPrefix = "cpp:source-ext:";
+    DefinitionContextPtr dc = unit->findDefinitionContext(file);
+    assert(dc);
+    string meta = dc->findMetaData(sourceExtPrefix);
+    if(meta.size() > sourceExtPrefix.size())
+    {
+        ext = meta.substr(sourceExtPrefix.size());
+    }
+    return ext;
+}
+
 // C++11 visitors
-Slice::Gen::Cpp11DeclVisitor::Cpp11DeclVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport)
+Slice::Gen::Cpp11DeclVisitor::Cpp11DeclVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport)
 {
 }
 
@@ -5295,8 +5330,8 @@ Slice::Gen::Cpp11DeclVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::Cpp11TypesVisitor::Cpp11TypesVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport), _dllClassExport(toDllClassExport(dllExport)),
+Slice::Gen::Cpp11TypesVisitor::Cpp11TypesVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport), _dllClassExport(toDllClassExport(dllExport)),
     _dllMemberExport(toDllMemberExport(dllExport)), _doneStaticSymbol(false), _useWstring(false)
 {
 }
@@ -5693,8 +5728,8 @@ Slice::Gen::Cpp11TypesVisitor::visitDictionary(const DictionaryPtr& p)
     }
 }
 
-Slice::Gen::Cpp11ProxyVisitor::Cpp11ProxyVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllClassExport(toDllClassExport(dllExport)), 
+Slice::Gen::Cpp11ProxyVisitor::Cpp11ProxyVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllClassExport(toDllClassExport(dllExport)), 
     _dllMemberExport(toDllMemberExport(dllExport)),
     _useWstring(false)
 {
@@ -6283,9 +6318,7 @@ Slice::Gen::Cpp11TypesVisitor::emitUpcall(const ExceptionPtr& base, const string
 
 Slice::Gen::Cpp11ObjectVisitor::Cpp11ObjectVisitor(::IceUtilInternal::Output& h,
                                                    ::IceUtilInternal::Output& c,
-                                                   const std::string& dllExport,
-                                                   int warningLevel) :
-    ParserVisitor(warningLevel),
+                                                   const std::string& dllExport) :
     H(h),
     C(c),
     _dllExport(dllExport),
@@ -6338,9 +6371,8 @@ Slice::Gen::Cpp11ValueVisitor::emitUpcall(const ClassDefPtr& base, const string&
 
 Slice::Gen::Cpp11LocalObjectVisitor::Cpp11LocalObjectVisitor(::IceUtilInternal::Output& h,
                                                              ::IceUtilInternal::Output& c,
-                                                             const std::string& dllExport,
-                                                             int warningLevel) :
-    Cpp11ObjectVisitor(h, c, dllExport, warningLevel)
+                                                             const std::string& dllExport) :
+    Cpp11ObjectVisitor(h, c, dllExport)
 {
 }
 
@@ -6687,9 +6719,8 @@ Slice::Gen::Cpp11LocalObjectVisitor::visitOperation(const OperationPtr& p)
 
 Slice::Gen::Cpp11InterfaceVisitor::Cpp11InterfaceVisitor(::IceUtilInternal::Output& h,
                                                          ::IceUtilInternal::Output& c,
-                                                         const std::string& dllExport,
-                                                         int warningLevel) :
-    Cpp11ObjectVisitor(h, c, dllExport, warningLevel)
+                                                         const std::string& dllExport) :
+    Cpp11ObjectVisitor(h, c, dllExport)
 {
 }
 
@@ -7142,9 +7173,8 @@ Slice::Gen::Cpp11InterfaceVisitor::visitOperation(const OperationPtr& p)
 
 Slice::Gen::Cpp11ValueVisitor::Cpp11ValueVisitor(::IceUtilInternal::Output& h,
                                                  ::IceUtilInternal::Output& c,
-                                                 const std::string& dllExport,
-                                                 int warningLevel) :
-    Cpp11ObjectVisitor(h, c, dllExport, warningLevel)
+                                                 const std::string& dllExport) :
+    Cpp11ObjectVisitor(h, c, dllExport)
 {
 }
 
@@ -7497,8 +7527,7 @@ Slice::Gen::Cpp11ObjectVisitor::emitOneShotConstructor(const ClassDefPtr& p)
     }
 }
 
-Slice::Gen::Cpp11StreamVisitor::Cpp11StreamVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::Cpp11StreamVisitor::Cpp11StreamVisitor(Output& h, Output& c, const string& dllExport) :
     H(h),
     C(c),
     _dllExport(dllExport)
@@ -7610,8 +7639,7 @@ Slice::Gen::Cpp11StreamVisitor::visitEnum(const EnumPtr& p)
 }
 
 
-Slice::Gen::Cpp11CompatibilityVisitor::Cpp11CompatibilityVisitor(Output& h, Output&, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::Gen::Cpp11CompatibilityVisitor::Cpp11CompatibilityVisitor(Output& h, Output&, const string& dllExport) :
     H(h),
     _dllExport(dllExport)
 {
@@ -7661,8 +7689,8 @@ Slice::Gen::Cpp11CompatibilityVisitor::visitClassDecl(const ClassDeclPtr& p)
     }
 }
 
-Slice::Gen::Cpp11ImplVisitor::Cpp11ImplVisitor(Output& h, Output& c, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), H(h), C(c), _dllExport(dllExport), _useWstring(false)
+Slice::Gen::Cpp11ImplVisitor::Cpp11ImplVisitor(Output& h, Output& c, const string& dllExport) :
+    H(h), C(c), _dllExport(dllExport), _useWstring(false)
 {
 }
 
diff --git a/cpp/src/slice2cpp/Gen.h b/cpp/src/slice2cpp/Gen.h
index 660267b0539..b27d791a106 100644
--- a/cpp/src/slice2cpp/Gen.h
+++ b/cpp/src/slice2cpp/Gen.h
@@ -31,8 +31,7 @@ public:
         bool,
         bool,
         bool,
-        bool,
-        int);
+        bool);
     ~Gen();
 
     void generate(const UnitPtr&);
@@ -52,6 +51,12 @@ private:
     // or an empty string if no global metadata was found.
     //
     std::string getHeaderExt(const std::string& file, const UnitPtr& unit);
+    
+    //
+    // Returns the source extension defined in the global metadata for a given file,
+    // or an empty string if no global metadata was found.
+    //
+    std::string getSourceExt(const std::string& file, const UnitPtr& unit);
 
     ::IceUtilInternal::Output H;
     ::IceUtilInternal::Output C;
@@ -72,13 +77,12 @@ private:
     bool _implCpp11;
     bool _checksum;
     bool _ice;
-    int _warningLevel;
 
     class TypesVisitor : private ::IceUtil::noncopyable, public ParserVisitor
     {
     public:
 
-        TypesVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        TypesVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -110,7 +114,7 @@ private:
     {
     public:
 
-        ProxyDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ProxyDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -129,7 +133,7 @@ private:
     {
     public:
 
-        ProxyVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ProxyVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -155,7 +159,7 @@ private:
     {
     public:
 
-        ObjectDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ObjectDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -174,7 +178,7 @@ private:
     {
     public:
 
-        ObjectVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ObjectVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -207,7 +211,7 @@ private:
     {
     public:
 
-        AsyncCallbackVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        AsyncCallbackVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -228,7 +232,7 @@ private:
     {
     public:
 
-        AsyncCallbackTemplateVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        AsyncCallbackTemplateVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -253,7 +257,7 @@ private:
     {
     public:
 
-        ImplVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ImplVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -283,7 +287,7 @@ private:
     {
     public:
 
-        AsyncVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        AsyncVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -305,7 +309,7 @@ private:
     {
     public:
 
-        AsyncImplVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        AsyncImplVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -329,7 +333,7 @@ private:
     {
     public:
 
-        StreamVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        StreamVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -351,7 +355,7 @@ private:
     {
     public:
 
-        Cpp11DeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11DeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -374,7 +378,7 @@ private:
     {
     public:
 
-        Cpp11TypesVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11TypesVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -408,7 +412,7 @@ private:
     {
     public:
 
-        Cpp11ProxyVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11ProxyVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -434,7 +438,7 @@ private:
     {
     public:
 
-        Cpp11ObjectVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11ObjectVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
     protected:
 
@@ -457,7 +461,7 @@ private:
     {
     public:
 
-        Cpp11LocalObjectVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11LocalObjectVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -472,7 +476,7 @@ private:
     {
     public:
 
-        Cpp11InterfaceVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11InterfaceVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -488,7 +492,7 @@ private:
     {
     public:
 
-        Cpp11ValueVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11ValueVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -504,7 +508,7 @@ private:
     {
     public:
 
-        Cpp11StreamVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11StreamVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -525,7 +529,7 @@ private:
     {
     public:
 
-        Cpp11CompatibilityVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11CompatibilityVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -541,7 +545,7 @@ private:
     {
     public:
 
-        Cpp11ImplVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        Cpp11ImplVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -573,8 +577,6 @@ private:
     {
     public:
 
-        MetaDataVisitor(int);
-
         virtual bool visitUnitStart(const UnitPtr&);
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -602,7 +604,7 @@ private:
     {
     public:
 
-        NormalizeMetaDataVisitor(bool, int);
+        NormalizeMetaDataVisitor(bool);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual bool visitModuleStart(const ModulePtr&);
@@ -628,8 +630,8 @@ private:
         bool _cpp11;
     };
 
-    static void validateMetaData(const UnitPtr&, int);
-    static void normalizeMetaData(const UnitPtr&, bool, int);
+    static void validateMetaData(const UnitPtr&);
+    static void normalizeMetaData(const UnitPtr&, bool);
 };
 
 }
diff --git a/cpp/src/slice2cpp/Main.cpp b/cpp/src/slice2cpp/Main.cpp
index 83b19b943c9..7378da1b118 100644
--- a/cpp/src/slice2cpp/Main.cpp
+++ b/cpp/src/slice2cpp/Main.cpp
@@ -88,7 +88,6 @@ usage(const string& n)
         "                         deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore             Allow underscores in Slice identifiers\n"
         "                         deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn                Disable all warnings.\n"
         ;
 }
 
@@ -118,7 +117,6 @@ compile(const vector<string>& argv)
     opts.addOpt("", "ice");
     opts.addOpt("", "underscore");
     opts.addOpt("", "checksum");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
     vector<string> args;
@@ -199,8 +197,6 @@ compile(const vector<string>& argv)
 
     bool checksum = opts.isSet("checksum");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -333,7 +329,7 @@ compile(const vector<string>& argv)
                     try
                     {
                         Gen gen(icecpp->getBaseName(), headerExtension, sourceExtension, extraHeaders, include,
-                                includePaths, dllExport, output, implCpp98, implCpp11, checksum, ice, warningLevel);
+                                includePaths, dllExport, output, implCpp98, implCpp11, checksum, ice);
                         gen.generate(u);
                     }
                     catch(const Slice::FileException& ex)
diff --git a/cpp/src/slice2cs/CsUtil.cpp b/cpp/src/slice2cs/CsUtil.cpp
index 5de4582dd56..dac1c6a362e 100644
--- a/cpp/src/slice2cs/CsUtil.cpp
+++ b/cpp/src/slice2cs/CsUtil.cpp
@@ -2335,16 +2335,12 @@ Slice::CsGenerator::toArrayAlloc(const string& decl, const string& sz)
 }
 
 void
-Slice::CsGenerator::validateMetaData(const UnitPtr& u, int warningLevel)
+Slice::CsGenerator::validateMetaData(const UnitPtr& u)
 {
-    MetaDataVisitor visitor(warningLevel);
+    MetaDataVisitor visitor;
     u->visit(&visitor, true);
 }
 
-Slice::CsGenerator::MetaDataVisitor::MetaDataVisitor(int warningLevel) : ParserVisitor(warningLevel)
-{
-}
-
 bool
 Slice::CsGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
 {
@@ -2352,7 +2348,6 @@ Slice::CsGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
     // Validate global metadata in the top-level file and all included files.
     //
     StringList files = p->allFiles();
-
     for(StringList::iterator q = files.begin(); q != files.end(); ++q)
     {
         string file = *q;
@@ -2360,7 +2355,7 @@ Slice::CsGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
         assert(dc);
         StringList globalMetaData = dc->getMetaData();
         StringList newGlobalMetaData;
-
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         static const string csPrefix = "cs:";
         static const string clrPrefix = "clr:";
 
@@ -2379,7 +2374,7 @@ Slice::CsGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                 static const string csAttributePrefix = csPrefix + "attribute:";
                 if(s.find(csAttributePrefix) != 0 || s.size() == csAttributePrefix.size())
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         emitWarning(file, -1, "ignoring invalid global metadata `" + oldS + "'");
                     }
@@ -2504,6 +2499,11 @@ Slice::CsGenerator::MetaDataVisitor::validate(const ContainedPtr& cont)
     StringList localMetaData = cont->getMetaData();
     StringList newLocalMetaData;
 
+    const UnitPtr unit = cont->unit();
+    const DefinitionContextPtr dc = unit->findDefinitionContext(cont->file());
+    assert(dc);
+    bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
     for(StringList::iterator p = localMetaData.begin(); p != localMetaData.end(); ++p)
     {
         string& s = *p;
@@ -2547,7 +2547,7 @@ Slice::CsGenerator::MetaDataVisitor::validate(const ContainedPtr& cont)
                     string meta;
                     if(cont->findMetaData(csPrefix + "generic:", meta))
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             emitWarning(cont->file(), cont->line(), msg + " `" + meta + "':\n" +
                                         "serialization can only be used with the array mapping for byte sequences");
@@ -2623,7 +2623,7 @@ Slice::CsGenerator::MetaDataVisitor::validate(const ContainedPtr& cont)
                 continue;
             }
 
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 emitWarning(cont->file(), cont->line(), msg + " `" + oldS + "'");
             }
@@ -2638,7 +2638,7 @@ Slice::CsGenerator::MetaDataVisitor::validate(const ContainedPtr& cont)
                 continue;
             }
 
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 emitWarning(cont->file(), cont->line(), msg + " `" + s + "'");
             }
diff --git a/cpp/src/slice2cs/CsUtil.h b/cpp/src/slice2cs/CsUtil.h
index 1741150f100..16ebd8a3c54 100644
--- a/cpp/src/slice2cs/CsUtil.h
+++ b/cpp/src/slice2cs/CsUtil.h
@@ -30,7 +30,7 @@ public:
     //
     // Validate all metadata in the unit with a "cs:" prefix.
     //
-    static void validateMetaData(const UnitPtr&, int);
+    static void validateMetaData(const UnitPtr&);
 
 protected:
 
@@ -65,8 +65,6 @@ private:
     {
     public:
 
-        MetaDataVisitor(int);
-
         virtual bool visitUnitStart(const UnitPtr&);
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
diff --git a/cpp/src/slice2cs/Gen.cpp b/cpp/src/slice2cs/Gen.cpp
index c1377db72cd..0008249211a 100644
--- a/cpp/src/slice2cs/Gen.cpp
+++ b/cpp/src/slice2cs/Gen.cpp
@@ -154,8 +154,7 @@ resultStructReturnValueName(const ParamDeclList& outParams)
 
 }
 
-Slice::CsVisitor::CsVisitor(Output& out, int warningLevel) :
-    ParserVisitor(warningLevel),
+Slice::CsVisitor::CsVisitor(Output& out) :
     _out(out)
 {
 }
@@ -2021,10 +2020,9 @@ Slice::CsVisitor::writeDocCommentParam(const OperationPtr& p, ParamDir paramType
 }
 
 Slice::Gen::Gen(const string& base, const vector<string>& includePaths, const string& dir,
-                bool tie, bool impl, bool implTie, int warningLevel) :
+                bool tie, bool impl, bool implTie) :
     _includePaths(includePaths),
-    _tie(tie),
-	_warningLevel(warningLevel)
+    _tie(tie)
 {
     string fileBase = base;
     string::size_type pos = base.find_last_of("/\\");
@@ -2094,58 +2092,58 @@ Slice::Gen::~Gen()
 void
 Slice::Gen::generate(const UnitPtr& p)
 {
-    CsGenerator::validateMetaData(p, _warningLevel);
+    CsGenerator::validateMetaData(p);
 
-    UnitVisitor unitVisitor(_out, _warningLevel);
+    UnitVisitor unitVisitor(_out);
     p->visit(&unitVisitor, false);
 
-    CompactIdVisitor compactIdVisitor(_out, _warningLevel);
+    CompactIdVisitor compactIdVisitor(_out);
     p->visit(&compactIdVisitor, false);
 
-    TypesVisitor typesVisitor(_out, _warningLevel);
+    TypesVisitor typesVisitor(_out);
     p->visit(&typesVisitor, false);
 
     //
     // The async delegates are emitted before the proxy definition
     // because the proxy methods need to know the type.
     //
-    AsyncDelegateVisitor asyncDelegateVisitor(_out, _warningLevel);
+    AsyncDelegateVisitor asyncDelegateVisitor(_out);
     p->visit(&asyncDelegateVisitor, false);
 
-    ResultVisitor resultVisitor(_out, _warningLevel);
+    ResultVisitor resultVisitor(_out);
     p->visit(&resultVisitor, false);
 
-    ProxyVisitor proxyVisitor(_out, _warningLevel);
+    ProxyVisitor proxyVisitor(_out);
     p->visit(&proxyVisitor, false);
 
-    OpsVisitor opsVisitor(_out, _warningLevel);
+    OpsVisitor opsVisitor(_out);
     p->visit(&opsVisitor, false);
 
-    HelperVisitor helperVisitor(_out, _warningLevel);
+    HelperVisitor helperVisitor(_out);
     p->visit(&helperVisitor, false);
 
-    DispatcherVisitor dispatcherVisitor(_out, _tie, _warningLevel);
+    DispatcherVisitor dispatcherVisitor(_out, _tie);
     p->visit(&dispatcherVisitor, false);
 }
 
 void
 Slice::Gen::generateImpl(const UnitPtr& p)
 {
-    ImplVisitor implVisitor(_impl, _warningLevel);
+    ImplVisitor implVisitor(_impl);
     p->visit(&implVisitor, false);
 }
 
 void
 Slice::Gen::generateImplTie(const UnitPtr& p)
 {
-    ImplTieVisitor implTieVisitor(_impl, _warningLevel);
+    ImplTieVisitor implTieVisitor(_impl);
     p->visit(&implTieVisitor, false);
 }
 
 void
 Slice::Gen::generateChecksums(const UnitPtr& u)
 {
-    ChecksumMap map = createChecksums(u, _warningLevel);
+    ChecksumMap map = createChecksums(u);
     if(!map.empty())
     {
         string className = "X" + generateUUID();
@@ -2214,8 +2212,8 @@ Slice::Gen::printHeader()
     _out << "//\n";
 }
 
-Slice::Gen::UnitVisitor::UnitVisitor(IceUtilInternal::Output& out, int warningLevel) :
-    CsVisitor(out, warningLevel)
+Slice::Gen::UnitVisitor::UnitVisitor(IceUtilInternal::Output& out) :
+    CsVisitor(out)
 {
 }
 
@@ -2246,8 +2244,8 @@ Slice::Gen::UnitVisitor::visitUnitStart(const UnitPtr& p)
     return false;
 }
 
-Slice::Gen::CompactIdVisitor::CompactIdVisitor(IceUtilInternal::Output& out, int warningLevel) :
-    CsVisitor(out, warningLevel)
+Slice::Gen::CompactIdVisitor::CompactIdVisitor(IceUtilInternal::Output& out) :
+    CsVisitor(out)
 {
 }
 
@@ -2280,8 +2278,8 @@ Slice::Gen::CompactIdVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::Gen::TypesVisitor::TypesVisitor(IceUtilInternal::Output& out, int warningLevel) :
-    CsVisitor(out, warningLevel)
+Slice::Gen::TypesVisitor::TypesVisitor(IceUtilInternal::Output& out) :
+    CsVisitor(out)
 {
 }
 
@@ -3767,8 +3765,8 @@ Slice::Gen::TypesVisitor::writeMemberEquals(const DataMemberList& dataMembers, i
     }
 }
 
-Slice::Gen::ResultVisitor::ResultVisitor(::IceUtilInternal::Output& out, int warningLevel)
-    : CsVisitor(out, warningLevel)
+Slice::Gen::ResultVisitor::ResultVisitor(::IceUtilInternal::Output& out)
+    : CsVisitor(out)
 {
 }
 
@@ -3926,8 +3924,8 @@ Slice::Gen::ResultVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::ProxyVisitor::ProxyVisitor(IceUtilInternal::Output& out, int warningLevel) :
-    CsVisitor(out, warningLevel)
+Slice::Gen::ProxyVisitor::ProxyVisitor(IceUtilInternal::Output& out) :
+    CsVisitor(out)
 {
 }
 
@@ -4114,8 +4112,8 @@ Slice::Gen::ProxyVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::AsyncDelegateVisitor::AsyncDelegateVisitor(IceUtilInternal::Output& out, int warningLevel)
-    : CsVisitor(out, warningLevel)
+Slice::Gen::AsyncDelegateVisitor::AsyncDelegateVisitor(IceUtilInternal::Output& out)
+    : CsVisitor(out)
 {
 }
 
@@ -4171,8 +4169,8 @@ Slice::Gen::AsyncDelegateVisitor::visitOperation(const OperationPtr& p)
     _out << paramDeclAMI << epar << ';';
 }
 
-Slice::Gen::OpsVisitor::OpsVisitor(IceUtilInternal::Output& out, int warningLevel)
-    : CsVisitor(out, warningLevel)
+Slice::Gen::OpsVisitor::OpsVisitor(IceUtilInternal::Output& out)
+    : CsVisitor(out)
 {
 }
 
@@ -4269,8 +4267,8 @@ Slice::Gen::OpsVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::Gen::HelperVisitor::HelperVisitor(IceUtilInternal::Output& out, int warningLevel) :
-    CsVisitor(out, warningLevel)
+Slice::Gen::HelperVisitor::HelperVisitor(IceUtilInternal::Output& out) :
+    CsVisitor(out)
 {
 }
 
@@ -5200,8 +5198,8 @@ Slice::Gen::HelperVisitor::visitDictionary(const DictionaryPtr& p)
     _out << eb;
 }
 
-Slice::Gen::DispatcherVisitor::DispatcherVisitor(::IceUtilInternal::Output& out, bool tie, int warningLevel) :
-    CsVisitor(out, warningLevel),
+Slice::Gen::DispatcherVisitor::DispatcherVisitor(::IceUtilInternal::Output& out, bool tie) :
+    CsVisitor(out),
     _tie(tie)
 {
 }
@@ -5414,8 +5412,8 @@ Slice::Gen::DispatcherVisitor::writeTieOperations(const ClassDefPtr& p, NameSet*
     }
 }
 
-Slice::Gen::BaseImplVisitor::BaseImplVisitor(IceUtilInternal::Output& out, int warningLevel)
-    : CsVisitor(out, warningLevel)
+Slice::Gen::BaseImplVisitor::BaseImplVisitor(IceUtilInternal::Output& out)
+    : CsVisitor(out)
 {
 }
 
@@ -5522,8 +5520,8 @@ Slice::Gen::BaseImplVisitor::writeOperation(const OperationPtr& op, bool comment
     }
 }
 
-Slice::Gen::ImplVisitor::ImplVisitor(IceUtilInternal::Output& out, int warningLevel) :
-    BaseImplVisitor(out, warningLevel)
+Slice::Gen::ImplVisitor::ImplVisitor(IceUtilInternal::Output& out) :
+    BaseImplVisitor(out)
 {
 }
 
@@ -5590,8 +5588,8 @@ Slice::Gen::ImplVisitor::visitClassDefEnd(const ClassDefPtr&)
     _out << eb;
 }
 
-Slice::Gen::ImplTieVisitor::ImplTieVisitor(IceUtilInternal::Output& out, int warningLevel)
-    : BaseImplVisitor(out, warningLevel)
+Slice::Gen::ImplTieVisitor::ImplTieVisitor(IceUtilInternal::Output& out)
+    : BaseImplVisitor(out)
 {
 }
 
diff --git a/cpp/src/slice2cs/Gen.h b/cpp/src/slice2cs/Gen.h
index f07bbc77cdc..d061616693d 100644
--- a/cpp/src/slice2cs/Gen.h
+++ b/cpp/src/slice2cs/Gen.h
@@ -20,7 +20,7 @@ class CsVisitor : public CsGenerator, public ParserVisitor
 {
 public:
 
-    CsVisitor(::IceUtilInternal::Output&, int);
+    CsVisitor(::IceUtilInternal::Output&);
     virtual ~CsVisitor();
 
 protected:
@@ -87,8 +87,7 @@ public:
         const std::string&,
         bool,
         bool,
-        bool,
-        int);
+        bool);
     ~Gen();
 
     void generate(const UnitPtr&);
@@ -103,7 +102,6 @@ private:
     IceUtilInternal::Output _impl;
     std::vector<std::string> _includePaths;
     bool _tie;
-    int _warningLevel;
 
     void printHeader();
 
@@ -111,7 +109,7 @@ private:
     {
     public:
 
-        UnitVisitor(::IceUtilInternal::Output&, int);
+        UnitVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitUnitStart(const UnitPtr&);
     };
@@ -120,7 +118,7 @@ private:
     {
     public:
 
-        CompactIdVisitor(IceUtilInternal::Output&, int);
+        CompactIdVisitor(IceUtilInternal::Output&);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -131,7 +129,7 @@ private:
     {
     public:
 
-        TypesVisitor(::IceUtilInternal::Output&, int);
+        TypesVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -158,7 +156,7 @@ private:
     {
     public:
 
-        AsyncDelegateVisitor(::IceUtilInternal::Output&, int);
+        AsyncDelegateVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -171,7 +169,7 @@ private:
     {
     public:
 
-        ResultVisitor(::IceUtilInternal::Output&, int);
+        ResultVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -184,7 +182,7 @@ private:
     {
     public:
 
-        ProxyVisitor(::IceUtilInternal::Output&, int);
+        ProxyVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -197,7 +195,7 @@ private:
     {
     public:
 
-        OpsVisitor(::IceUtilInternal::Output&, int);
+        OpsVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -208,7 +206,7 @@ private:
     {
     public:
 
-        HelperVisitor(::IceUtilInternal::Output&, int);
+        HelperVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -222,7 +220,7 @@ private:
     {
     public:
 
-        DispatcherVisitor(::IceUtilInternal::Output&, bool, int);
+        DispatcherVisitor(::IceUtilInternal::Output&, bool);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -241,7 +239,7 @@ private:
     {
     public:
 
-        BaseImplVisitor(::IceUtilInternal::Output&, int);
+        BaseImplVisitor(::IceUtilInternal::Output&);
 
     protected:
 
@@ -252,7 +250,7 @@ private:
     {
     public:
 
-        ImplVisitor(::IceUtilInternal::Output&, int);
+        ImplVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -264,7 +262,7 @@ private:
     {
     public:
 
-        ImplTieVisitor(::IceUtilInternal::Output&, int);
+        ImplTieVisitor(::IceUtilInternal::Output&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
diff --git a/cpp/src/slice2cs/Main.cpp b/cpp/src/slice2cs/Main.cpp
index 31b60cee93d..21738ba6f83 100644
--- a/cpp/src/slice2cs/Main.cpp
+++ b/cpp/src/slice2cs/Main.cpp
@@ -82,7 +82,6 @@ usage(const string& n)
         "                        deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore            Allow underscores in Slice identifiers\n"
         "                        deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn               Disable all warnings.\n"
         ;
 }
 
@@ -108,7 +107,6 @@ compile(const vector<string>& argv)
     opts.addOpt("", "ice");
     opts.addOpt("", "underscore");
     opts.addOpt("", "checksum");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
     vector<string> args;
@@ -181,8 +179,6 @@ compile(const vector<string>& argv)
 
     bool checksum = opts.isSet("checksum");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -313,7 +309,7 @@ compile(const vector<string>& argv)
                 {
                     try
                     {
-                        Gen gen(icecpp->getBaseName(), includePaths, output, tie, impl, implTie, warningLevel);
+                        Gen gen(icecpp->getBaseName(), includePaths, output, tie, impl, implTie);
                         gen.generate(p);
                         if(impl)
                         {
diff --git a/cpp/src/slice2html/Gen.cpp b/cpp/src/slice2html/Gen.cpp
index bd226fbd027..54383af7030 100644
--- a/cpp/src/slice2html/Gen.cpp
+++ b/cpp/src/slice2html/Gen.cpp
@@ -37,7 +37,7 @@ namespace Slice
 void
 generate(const UnitPtr& unit, const string& dir, const string& header, const string& footer,
          const string& indexHeader, const string& indexFooter, const string& imageDir, const string& logoURL,
-         const string& searchAction, unsigned indexCount, unsigned warnSummary, int warningLevel)
+         const string& searchAction, unsigned indexCount, unsigned warnSummary)
 {
     unit->mergeModules();
 
@@ -66,19 +66,19 @@ generate(const UnitPtr& unit, const string& dir, const string& header, const str
     // to the symbol; if the latter, we cannot.
     //
     Files files;
-    FileVisitor tv(files, warningLevel);
+    FileVisitor tv(files);
     unit->visit(&tv, false);
 
     //
     // Generate the start page.
     //
-    StartPageVisitor spv(files, warningLevel);
+    StartPageVisitor spv(files);
     unit->visit(&spv, false);
 
     //
     // Generate the table of contents.
     //
-    TOCVisitor tocv(files, indexHeader, indexFooter, warningLevel);
+    TOCVisitor tocv(files, indexHeader, indexFooter);
     unit->visit(&tocv, false);
     tocv.generate();
 
@@ -86,7 +86,7 @@ generate(const UnitPtr& unit, const string& dir, const string& header, const str
     // Generate the individual HTML pages.
     //
     GeneratorBase::setSymbols(tocv.symbols());
-    PageVisitor v(files, warningLevel);
+    PageVisitor v(files);
     unit->visit(&v, false);
 }
 
@@ -1800,8 +1800,7 @@ Slice::StartPageGenerator::printHeaderFooter()
     end(); // table
 }
 
-Slice::FileVisitor::FileVisitor(Files& files, int warningLevel) :
-	ParserVisitor(warningLevel),
+Slice::FileVisitor::FileVisitor(Files& files) :
     _files(files)
 {
 }
@@ -1864,8 +1863,7 @@ Slice::FileVisitor::visitEnum(const EnumPtr& e)
     _files.insert(e->file());
 }
 
-Slice::StartPageVisitor::StartPageVisitor(const Files& files, int warningLevel) :
-	ParserVisitor(warningLevel),
+Slice::StartPageVisitor::StartPageVisitor(const Files& files) :
     _spg(files)
 {
 }
@@ -2043,8 +2041,7 @@ TOCGenerator::writeEntry(const ContainedPtr& c)
     end();
 }
 
-TOCVisitor::TOCVisitor(const Files& files, const string& header, const string& footer, int warningLevel) :
-	ParserVisitor(warningLevel),
+TOCVisitor::TOCVisitor(const Files& files, const string& header, const string& footer) :
     _tg(files, header, footer)
 {
 }
@@ -2979,8 +2976,7 @@ Slice::EnumGenerator::generate(const EnumPtr& e)
     assert(_out.currIndent() == indent);
 }
 
-Slice::PageVisitor::PageVisitor(const Files& files, int warningLevel) :
-	ParserVisitor(warningLevel),
+Slice::PageVisitor::PageVisitor(const Files& files) :
 	_files(files)
 {
 }
diff --git a/cpp/src/slice2html/Gen.h b/cpp/src/slice2html/Gen.h
index b38556e4bb2..8fb67136bc0 100644
--- a/cpp/src/slice2html/Gen.h
+++ b/cpp/src/slice2html/Gen.h
@@ -18,7 +18,7 @@ namespace Slice
 
 void generate(const UnitPtr&, const ::std::string&, const ::std::string&, const ::std::string&, const std::string&,
               const ::std::string&, const ::std::string&, const ::std::string&, const ::std::string&,
-              unsigned, unsigned, int);
+              unsigned, unsigned);
 
 typedef ::std::set< ::std::string> Files;
 
@@ -141,7 +141,7 @@ class FileVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    FileVisitor(Files&, int);
+    FileVisitor(Files&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
@@ -162,7 +162,7 @@ class StartPageVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    StartPageVisitor(const Files&, int);
+    StartPageVisitor(const Files&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
@@ -195,7 +195,7 @@ class TOCVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    TOCVisitor(const Files&, const ::std::string&, const ::std::string&, int);
+    TOCVisitor(const Files&, const ::std::string&, const ::std::string&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
@@ -255,7 +255,7 @@ class PageVisitor : private ::IceUtil::noncopyable, public ParserVisitor
 {
 public:
 
-    PageVisitor(const Files&, int);
+    PageVisitor(const Files&);
 
     virtual bool visitUnitStart(const UnitPtr&);
     virtual bool visitModuleStart(const ModulePtr&);
diff --git a/cpp/src/slice2html/Main.cpp b/cpp/src/slice2html/Main.cpp
index 7b5a6562968..ae2bfaa75ff 100644
--- a/cpp/src/slice2html/Main.cpp
+++ b/cpp/src/slice2html/Main.cpp
@@ -85,7 +85,6 @@ usage(const string& n)
         "                     deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore         Allow underscores in Slice identifiers\n"
         "                     deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn            Disable all warnings.\n"
         ;
 }
 
@@ -113,7 +112,6 @@ compile(const vector<string>& argv)
     opts.addOpt("d", "debug");
     opts.addOpt("", "ice");
     opts.addOpt("", "underscore");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
     vector<string> args;
@@ -222,8 +220,6 @@ compile(const vector<string>& argv)
 
     bool underscore = opts.isSet("underscore");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -294,7 +290,7 @@ compile(const vector<string>& argv)
         try
         {
             Slice::generate(p, output, header, footer, indexHeader, indexFooter, imageDir, logoURL,
-                            searchAction, indexCount, summaryCount, warningLevel);
+                            searchAction, indexCount, summaryCount);
         }
         catch(const Slice::FileException& ex)
         {
diff --git a/cpp/src/slice2java/Gen.cpp b/cpp/src/slice2java/Gen.cpp
index 376a8edd86e..f33a44286cd 100644
--- a/cpp/src/slice2java/Gen.cpp
+++ b/cpp/src/slice2java/Gen.cpp
@@ -144,9 +144,8 @@ string ofFactory(const TypePtr& type)
 
 }
 
-Slice::JavaVisitor::JavaVisitor(const string& dir, int warningLevel) :
-    JavaGenerator(dir),
-    ParserVisitor(warningLevel)
+Slice::JavaVisitor::JavaVisitor(const string& dir) :
+    JavaGenerator(dir)
 {
 }
 
@@ -2299,12 +2298,10 @@ Slice::JavaVisitor::writeServantDocComment(Output& out, const OperationPtr& p, c
     out << nl << " **/";
 }
 
-Slice::Gen::Gen(const string& /*name*/, const string& base, const vector<string>& includePaths, const string& dir,
-                int warningLevel) :
+Slice::Gen::Gen(const string& /*name*/, const string& base, const vector<string>& includePaths, const string& dir) :
     _base(base),
     _includePaths(includePaths),
-    _dir(dir),
-    _warningLevel(warningLevel)
+    _dir(dir)
 {
 }
 
@@ -2315,31 +2312,31 @@ Slice::Gen::~Gen()
 void
 Slice::Gen::generate(const UnitPtr& p)
 {
-    JavaGenerator::validateMetaData(p, _warningLevel);
+    JavaGenerator::validateMetaData(p);
 
-    PackageVisitor packageVisitor(_dir, _warningLevel);
+    PackageVisitor packageVisitor(_dir);
     p->visit(&packageVisitor, false);
 
-    TypesVisitor typesVisitor(_dir, _warningLevel);
+    TypesVisitor typesVisitor(_dir);
     p->visit(&typesVisitor, false);
 
-    CompactIdVisitor compactIdVisitor(_dir, _warningLevel);
+    CompactIdVisitor compactIdVisitor(_dir);
     p->visit(&compactIdVisitor, false);
 
-    HelperVisitor helperVisitor(_dir, _warningLevel);
+    HelperVisitor helperVisitor(_dir);
     p->visit(&helperVisitor, false);
 
-    ProxyVisitor proxyVisitor(_dir, _warningLevel);
+    ProxyVisitor proxyVisitor(_dir);
     p->visit(&proxyVisitor, false);
 
-    DispatcherVisitor dispatcherVisitor(_dir, _warningLevel);
+    DispatcherVisitor dispatcherVisitor(_dir);
     p->visit(&dispatcherVisitor, false);
 }
 
 void
 Slice::Gen::generateImpl(const UnitPtr& p)
 {
-    ImplVisitor implVisitor(_dir, _warningLevel);
+    ImplVisitor implVisitor(_dir);
     p->visit(&implVisitor, false);
 }
 
@@ -2398,8 +2395,8 @@ Slice::Gen::writeChecksumClass(const string& checksumClass, const string& dir, c
     out << nl;
 }
 
-Slice::Gen::PackageVisitor::PackageVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::PackageVisitor::PackageVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
@@ -2423,8 +2420,8 @@ Slice::Gen::PackageVisitor::visitModuleStart(const ModulePtr& p)
     return false;
 }
 
-Slice::Gen::TypesVisitor::TypesVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::TypesVisitor::TypesVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
@@ -2760,10 +2757,15 @@ Slice::Gen::TypesVisitor::visitClassDefEnd(const ClassDefPtr& p)
         string serialVersionUID;
         if(p->findMetaData("java:serialVersionUID", serialVersionUID))
         {
+            const UnitPtr unit = p->unit();
+            const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+            assert(dc);
+            bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
             string::size_type pos = serialVersionUID.rfind(":") + 1;
             if(pos == string::npos)
             {
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     ostringstream os;
                     os << "ignoring invalid serialVersionUID for class `" << p->scoped() << "'; generating default value";
@@ -2779,7 +2781,7 @@ Slice::Gen::TypesVisitor::visitClassDefEnd(const ClassDefPtr& p)
                 {
                     if(!stringToInt64(serialVersionUID, v)) // conversion error
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             ostringstream os;
                             os << "ignoring invalid serialVersionUID for class `" << p->scoped()
@@ -3291,10 +3293,15 @@ Slice::Gen::TypesVisitor::visitExceptionEnd(const ExceptionPtr& p)
     string serialVersionUID;
     if(p->findMetaData("java:serialVersionUID", serialVersionUID))
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
+
         string::size_type pos = serialVersionUID.rfind(":") + 1;
         if(pos == string::npos)
         {
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 ostringstream os;
                 os << "ignoring invalid serialVersionUID for exception `" << p->scoped() << "'; generating default value";
@@ -3310,7 +3317,7 @@ Slice::Gen::TypesVisitor::visitExceptionEnd(const ExceptionPtr& p)
             {
                 if(!stringToInt64(serialVersionUID, v)) // conversion error
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         ostringstream os;
                         os << "ignoring invalid serialVersionUID for exception `" << p->scoped()
@@ -3610,10 +3617,14 @@ Slice::Gen::TypesVisitor::visitStructEnd(const StructPtr& p)
     string serialVersionUID;
     if(p->findMetaData("java:serialVersionUID", serialVersionUID))
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         string::size_type pos = serialVersionUID.rfind(":") + 1;
         if(pos == string::npos)
         {
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 ostringstream os;
                 os << "ignoring invalid serialVersionUID for struct `" << p->scoped() << "'; generating default value";
@@ -3629,7 +3640,7 @@ Slice::Gen::TypesVisitor::visitStructEnd(const StructPtr& p)
             {
                 if(!stringToInt64(serialVersionUID, v)) // conversion error
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         ostringstream os;
                         os << "ignoring invalid serialVersionUID for struct `" << p->scoped()
@@ -4160,8 +4171,8 @@ Slice::Gen::TypesVisitor::validateMethod(const OperationList& ops, const std::st
     return true;
 }
 
-Slice::Gen::CompactIdVisitor::CompactIdVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::CompactIdVisitor::CompactIdVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
@@ -4190,8 +4201,8 @@ Slice::Gen::CompactIdVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::Gen::HelperVisitor::HelperVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::HelperVisitor::HelperVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
@@ -4355,8 +4366,8 @@ Slice::Gen::HelperVisitor::visitDictionary(const DictionaryPtr& p)
     close();
 }
 
-Slice::Gen::ProxyVisitor::ProxyVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::ProxyVisitor::ProxyVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
@@ -5110,8 +5121,8 @@ Slice::Gen::ProxyVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::Gen::DispatcherVisitor::DispatcherVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::DispatcherVisitor::DispatcherVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
@@ -5184,8 +5195,8 @@ Slice::Gen::DispatcherVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::Gen::ImplVisitor::ImplVisitor(const string& dir, int warningLevel) :
-    JavaVisitor(dir, warningLevel)
+Slice::Gen::ImplVisitor::ImplVisitor(const string& dir) :
+    JavaVisitor(dir)
 {
 }
 
diff --git a/cpp/src/slice2java/Gen.h b/cpp/src/slice2java/Gen.h
index d2ce2ef44c1..11c7d0f7e45 100644
--- a/cpp/src/slice2java/Gen.h
+++ b/cpp/src/slice2java/Gen.h
@@ -25,7 +25,7 @@ public:
 
 protected:
 
-    JavaVisitor(const std::string&, int);
+    JavaVisitor(const std::string&);
 
     enum ParamDir { InParam, OutParam };
 
@@ -129,8 +129,7 @@ public:
     Gen(const std::string&,
         const std::string&,
         const std::vector<std::string>&,
-        const std::string&,
-        int);
+        const std::string&);
     ~Gen();
 
     void generate(const UnitPtr&);
@@ -143,13 +142,12 @@ private:
     std::string _base;
     std::vector<std::string> _includePaths;
     std::string _dir;
-    int _warningLevel;
 
     class PackageVisitor : public JavaVisitor
     {
     public:
 
-        PackageVisitor(const std::string&, int);
+        PackageVisitor(const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
     };
@@ -158,7 +156,7 @@ private:
     {
     public:
 
-        TypesVisitor(const std::string&, int);
+        TypesVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitClassDefEnd(const ClassDefPtr&);
@@ -183,7 +181,7 @@ private:
     {
     public:
 
-        CompactIdVisitor(const std::string&, int);
+        CompactIdVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
     };
@@ -192,7 +190,7 @@ private:
     {
     public:
 
-        HelperVisitor(const std::string&, int);
+        HelperVisitor(const std::string&);
 
         virtual void visitSequence(const SequencePtr&);
         virtual void visitDictionary(const DictionaryPtr&);
@@ -202,7 +200,7 @@ private:
     {
     public:
 
-        ProxyVisitor(const std::string&, int);
+        ProxyVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitClassDefEnd(const ClassDefPtr&);
@@ -213,7 +211,7 @@ private:
     {
     public:
 
-        DispatcherVisitor(const std::string&, int);
+        DispatcherVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
     };
@@ -222,7 +220,7 @@ private:
     {
     public:
 
-        ImplVisitor(const std::string&, int);
+        ImplVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
 
diff --git a/cpp/src/slice2java/GenCompat.cpp b/cpp/src/slice2java/GenCompat.cpp
index 6579642d280..a3f4179ed8f 100644
--- a/cpp/src/slice2java/GenCompat.cpp
+++ b/cpp/src/slice2java/GenCompat.cpp
@@ -191,9 +191,8 @@ writeParamList(Output& out, vector<string> params, bool end = true, bool newLine
 
 }
 
-Slice::JavaCompatVisitor::JavaCompatVisitor(const string& dir, int warningLevel) :
-    JavaCompatGenerator(dir),
-    ParserVisitor(warningLevel)
+Slice::JavaCompatVisitor::JavaCompatVisitor(const string& dir) :
+    JavaCompatGenerator(dir)
 {
 }
 
@@ -2280,12 +2279,11 @@ Slice::JavaCompatVisitor::writeDocCommentParam(Output& out, const OperationPtr&
 }
 
 Slice::GenCompat::GenCompat(const string& /*name*/, const string& base, const vector<string>& includePaths, 
-                            const string& dir, bool tie, int warningLevel) :
+                            const string& dir, bool tie) :
     _base(base),
     _includePaths(includePaths),
     _dir(dir),
-    _tie(tie),
-    _warningLevel(warningLevel)
+    _tie(tie)
 {
 }
 
@@ -2296,47 +2294,47 @@ Slice::GenCompat::~GenCompat()
 void
 Slice::GenCompat::generate(const UnitPtr& p)
 {
-    JavaGenerator::validateMetaData(p, _warningLevel);
+    JavaGenerator::validateMetaData(p);
 
-    OpsVisitor opsVisitor(_dir, _warningLevel);
+    OpsVisitor opsVisitor(_dir);
     p->visit(&opsVisitor, false);
 
-    PackageVisitor packageVisitor(_dir, _warningLevel);
+    PackageVisitor packageVisitor(_dir);
     p->visit(&packageVisitor, false);
 
-    TypesVisitor typesVisitor(_dir, _warningLevel);
+    TypesVisitor typesVisitor(_dir);
     p->visit(&typesVisitor, false);
 
-    CompactIdVisitor compactIdVisitor(_dir, _warningLevel);
+    CompactIdVisitor compactIdVisitor(_dir);
     p->visit(&compactIdVisitor, false);
 
-    HolderVisitor holderVisitor(_dir, _warningLevel);
+    HolderVisitor holderVisitor(_dir);
     p->visit(&holderVisitor, false);
 
-    HelperVisitor helperVisitor(_dir, _warningLevel);
+    HelperVisitor helperVisitor(_dir);
     p->visit(&helperVisitor, false);
 
-    ProxyVisitor proxyVisitor(_dir, _warningLevel);
+    ProxyVisitor proxyVisitor(_dir);
     p->visit(&proxyVisitor, false);
 
-    DispatcherVisitor dispatcherVisitor(_dir, _tie, _warningLevel);
+    DispatcherVisitor dispatcherVisitor(_dir, _tie);
     p->visit(&dispatcherVisitor, false);
 
-    AsyncVisitor asyncVisitor(_dir, _warningLevel);
+    AsyncVisitor asyncVisitor(_dir);
     p->visit(&asyncVisitor, false);
 }
 
 void
 Slice::GenCompat::generateImpl(const UnitPtr& p)
 {
-    ImplVisitor implVisitor(_dir, _warningLevel);
+    ImplVisitor implVisitor(_dir);
     p->visit(&implVisitor, false);
 }
 
 void
 Slice::GenCompat::generateImplTie(const UnitPtr& p)
 {
-    ImplTieVisitor implTieVisitor(_dir, _warningLevel);
+    ImplTieVisitor implTieVisitor(_dir);
     p->visit(&implTieVisitor, false);
 }
 
@@ -2395,8 +2393,8 @@ Slice::GenCompat::writeChecksumClass(const string& checksumClass, const string&
     out << nl;
 }
 
-Slice::GenCompat::OpsVisitor::OpsVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::OpsVisitor::OpsVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -2530,8 +2528,8 @@ Slice::GenCompat::OpsVisitor::writeOperations(const ClassDefPtr& p, bool noCurre
     close();
 }
 
-Slice::GenCompat::PackageVisitor::PackageVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::PackageVisitor::PackageVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -2555,8 +2553,8 @@ Slice::GenCompat::PackageVisitor::visitModuleStart(const ModulePtr& p)
     return false;
 }
 
-Slice::GenCompat::TypesVisitor::TypesVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::TypesVisitor::TypesVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -3014,10 +3012,14 @@ Slice::GenCompat::TypesVisitor::visitClassDefEnd(const ClassDefPtr& p)
     string serialVersionUID;
     if(p->findMetaData("java:serialVersionUID", serialVersionUID))
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         string::size_type pos = serialVersionUID.rfind(":") + 1;
         if(pos == string::npos)
         {
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 ostringstream os;
                 os << "ignoring invalid serialVersionUID for class `" << p->scoped() << "'; generating default value";
@@ -3033,7 +3035,7 @@ Slice::GenCompat::TypesVisitor::visitClassDefEnd(const ClassDefPtr& p)
             {
                 if(!stringToInt64(serialVersionUID, v)) // conversion error
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         ostringstream os;
                         os << "ignoring invalid serialVersionUID for class `" << p->scoped()
@@ -3440,10 +3442,14 @@ Slice::GenCompat::TypesVisitor::visitExceptionEnd(const ExceptionPtr& p)
     string serialVersionUID;
     if(p->findMetaData("java:serialVersionUID", serialVersionUID))
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         string::size_type pos = serialVersionUID.rfind(":") + 1;
         if(pos == string::npos)
         {
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 ostringstream os;
                 os << "ignoring invalid serialVersionUID for exception `" << p->scoped() << "'; generating default value";
@@ -3459,7 +3465,7 @@ Slice::GenCompat::TypesVisitor::visitExceptionEnd(const ExceptionPtr& p)
             {
                 if(!stringToInt64(serialVersionUID, v)) // conversion error
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         ostringstream os;
                         os << "ignoring invalid serialVersionUID for exception `" << p->scoped()
@@ -3762,10 +3768,14 @@ Slice::GenCompat::TypesVisitor::visitStructEnd(const StructPtr& p)
     string serialVersionUID;
     if(p->findMetaData("java:serialVersionUID", serialVersionUID))
     {
+        const UnitPtr unit = p->unit();
+        const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+        assert(dc);
+        bool emitWarnings = !dc->suppressWarning("invalid-metadata");
         string::size_type pos = serialVersionUID.rfind(":") + 1;
         if(pos == string::npos)
         {
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 ostringstream os;
                 os << "ignoring invalid serialVersionUID for struct `" << p->scoped() << "'; generating default value";
@@ -3781,7 +3791,7 @@ Slice::GenCompat::TypesVisitor::visitStructEnd(const StructPtr& p)
             {
                 if(!stringToInt64(serialVersionUID, v)) // conversion error
                 {
-                    if(warningLevel() > 0)
+                    if(emitWarnings)
                     {
                         ostringstream os;
                         os << "ignoring invalid serialVersionUID for struct `" << p->scoped()
@@ -4212,8 +4222,8 @@ Slice::GenCompat::TypesVisitor::validateMethod(const OperationList& ops, const s
     return true;
 }
 
-Slice::GenCompat::CompactIdVisitor::CompactIdVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::CompactIdVisitor::CompactIdVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -4242,8 +4252,8 @@ Slice::GenCompat::CompactIdVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::GenCompat::HolderVisitor::HolderVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::HolderVisitor::HolderVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -4391,8 +4401,8 @@ Slice::GenCompat::HolderVisitor::writeHolder(const TypePtr& p)
     close();
 }
 
-Slice::GenCompat::HelperVisitor::HelperVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::HelperVisitor::HelperVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -5324,8 +5334,8 @@ Slice::GenCompat::HelperVisitor::writeOperation(const ClassDefPtr& p, const stri
     }
 }
 
-Slice::GenCompat::ProxyVisitor::ProxyVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::ProxyVisitor::ProxyVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -5644,8 +5654,8 @@ Slice::GenCompat::ProxyVisitor::visitOperation(const OperationPtr& p)
     }
 }
 
-Slice::GenCompat::DispatcherVisitor::DispatcherVisitor(const string& dir, bool tie, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel),
+Slice::GenCompat::DispatcherVisitor::DispatcherVisitor(const string& dir, bool tie) :
+    JavaCompatVisitor(dir),
     _tie(tie)
 {
 }
@@ -5843,10 +5853,14 @@ Slice::GenCompat::DispatcherVisitor::visitClassDefStart(const ClassDefPtr& p)
         string serialVersionUID;
         if(p->findMetaData("java:serialVersionUID", serialVersionUID))
         {
+            const UnitPtr unit = p->unit();
+            const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+            assert(dc);
+            bool emitWarnings = !dc->suppressWarning("invalid-metadata");
             string::size_type pos = serialVersionUID.rfind(":") + 1;
             if(pos == string::npos)
             {
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     ostringstream os;
                     os << "ignoring invalid serialVersionUID for class `" << p->scoped() << "'; generating default value";
@@ -5862,7 +5876,7 @@ Slice::GenCompat::DispatcherVisitor::visitClassDefStart(const ClassDefPtr& p)
                 {
                     if(!stringToInt64(serialVersionUID, v)) // conversion error
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             ostringstream os;
                             os << "ignoring invalid serialVersionUID for class `" << p->scoped()
@@ -5887,8 +5901,8 @@ Slice::GenCompat::DispatcherVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::GenCompat::BaseImplVisitor::BaseImplVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::BaseImplVisitor::BaseImplVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
@@ -6152,8 +6166,8 @@ Slice::GenCompat::BaseImplVisitor::writeOperation(Output& out, const string& pac
     }
 }
 
-Slice::GenCompat::ImplVisitor::ImplVisitor(const string& dir, int warningLevel) :
-    BaseImplVisitor(dir, warningLevel)
+Slice::GenCompat::ImplVisitor::ImplVisitor(const string& dir) :
+    BaseImplVisitor(dir)
 {
 }
 
@@ -6208,8 +6222,8 @@ Slice::GenCompat::ImplVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::GenCompat::ImplTieVisitor::ImplTieVisitor(const string& dir, int warningLevel) :
-    BaseImplVisitor(dir, warningLevel)
+Slice::GenCompat::ImplTieVisitor::ImplTieVisitor(const string& dir) :
+    BaseImplVisitor(dir)
 {
 }
 
@@ -6297,8 +6311,8 @@ Slice::GenCompat::ImplTieVisitor::visitClassDefStart(const ClassDefPtr& p)
     return false;
 }
 
-Slice::GenCompat::AsyncVisitor::AsyncVisitor(const string& dir, int warningLevel) :
-    JavaCompatVisitor(dir, warningLevel)
+Slice::GenCompat::AsyncVisitor::AsyncVisitor(const string& dir) :
+    JavaCompatVisitor(dir)
 {
 }
 
diff --git a/cpp/src/slice2java/GenCompat.h b/cpp/src/slice2java/GenCompat.h
index 25d2d0b7091..5f8ba85aa9d 100644
--- a/cpp/src/slice2java/GenCompat.h
+++ b/cpp/src/slice2java/GenCompat.h
@@ -25,7 +25,7 @@ public:
 
 protected:
 
-    JavaCompatVisitor(const std::string&, int);
+    JavaCompatVisitor(const std::string&);
 
     enum ParamDir { InParam, OutParam };
 
@@ -131,8 +131,7 @@ public:
               const std::string&,
               const std::vector<std::string>&,
               const std::string&,
-              bool,
-              int);
+              bool);
     ~GenCompat();
 
     void generate(const UnitPtr&);
@@ -147,13 +146,12 @@ private:
     std::vector<std::string> _includePaths;
     std::string _dir;
     bool _tie;
-    int _warningLevel;
 
     class OpsVisitor : public JavaCompatVisitor
     {
     public:
 
-        OpsVisitor(const std::string&, int);
+        OpsVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
 
@@ -165,7 +163,7 @@ private:
     {
     public:
 
-        PackageVisitor(const std::string&, int);
+        PackageVisitor(const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
     };
@@ -174,7 +172,7 @@ private:
     {
     public:
 
-        TypesVisitor(const std::string&, int);
+        TypesVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitClassDefEnd(const ClassDefPtr&);
@@ -198,7 +196,7 @@ private:
     {
     public:
 
-        CompactIdVisitor(const std::string&, int);
+        CompactIdVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
     };
@@ -207,7 +205,7 @@ private:
     {
     public:
 
-        HolderVisitor(const std::string&, int);
+        HolderVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual bool visitStructStart(const StructPtr&);
@@ -224,7 +222,7 @@ private:
     {
     public:
 
-        HelperVisitor(const std::string&, int);
+        HelperVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitSequence(const SequencePtr&);
@@ -239,7 +237,7 @@ private:
     {
     public:
 
-        ProxyVisitor(const std::string&, int);
+        ProxyVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitClassDefEnd(const ClassDefPtr&);
@@ -250,7 +248,7 @@ private:
     {
     public:
 
-        DispatcherVisitor(const std::string&, bool, int);
+        DispatcherVisitor(const std::string&, bool);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
 
@@ -262,7 +260,7 @@ private:
     {
     public:
 
-        BaseImplVisitor(const std::string&, int);
+        BaseImplVisitor(const std::string&);
 
     protected:
 
@@ -288,7 +286,7 @@ private:
     {
     public:
 
-        ImplVisitor(const std::string&, int);
+        ImplVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
     };
@@ -297,7 +295,7 @@ private:
     {
     public:
 
-        ImplTieVisitor(const std::string&, int);
+        ImplTieVisitor(const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
     };
@@ -306,7 +304,7 @@ private:
     {
     public:
 
-        AsyncVisitor(const std::string&, int);
+        AsyncVisitor(const std::string&);
 
         virtual void visitOperation(const OperationPtr&);
     };
diff --git a/cpp/src/slice2java/Main.cpp b/cpp/src/slice2java/Main.cpp
index c14a467d3b7..a1ff63c6127 100644
--- a/cpp/src/slice2java/Main.cpp
+++ b/cpp/src/slice2java/Main.cpp
@@ -87,7 +87,6 @@ usage(const string& n)
         "                        deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore            Allow underscores in Slice identifiers\n"
         "                        deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn               Disable all warnings.\n"
         ;
 }
 
@@ -116,7 +115,6 @@ compile(const vector<string>& argv)
     opts.addOpt("", "checksum", IceUtilInternal::Options::NeedArg);
     opts.addOpt("", "meta", IceUtilInternal::Options::NeedArg, "", IceUtilInternal::Options::Repeat);
     opts.addOpt("", "compat");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
     vector<string>args;
@@ -195,8 +193,6 @@ compile(const vector<string>& argv)
 
     bool compat = opts.isSet("compat");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -354,7 +350,7 @@ compile(const vector<string>& argv)
                     {
                         if(compat)
                         {
-                            GenCompat gen(argv[0], icecpp->getBaseName(), includePaths, output, tie, warningLevel);
+                            GenCompat gen(argv[0], icecpp->getBaseName(), includePaths, output, tie);
                             gen.generate(p);
                             if(impl)
                             {
@@ -367,7 +363,7 @@ compile(const vector<string>& argv)
                         }
                         else
                         {
-                            Gen gen(argv[0], icecpp->getBaseName(), includePaths, output, warningLevel);
+                            Gen gen(argv[0], icecpp->getBaseName(), includePaths, output);
                             gen.generate(p);
                             if(impl)
                             {
@@ -380,7 +376,7 @@ compile(const vector<string>& argv)
                             //
                             // Calculate checksums for the Slice definitions in the unit.
                             //
-                            ChecksumMap m = createChecksums(p, warningLevel);
+                            ChecksumMap m = createChecksums(p);
                             copy(m.begin(), m.end(), inserter(checksums, checksums.begin()));
                         }
                         if(listGenerated)
diff --git a/cpp/src/slice2js/Gen.cpp b/cpp/src/slice2js/Gen.cpp
index 74297f80738..29c1c9f47dc 100644
--- a/cpp/src/slice2js/Gen.cpp
+++ b/cpp/src/slice2js/Gen.cpp
@@ -89,7 +89,7 @@ getDeprecateReason(const ContainedPtr& p1, const ContainedPtr& p2, const string&
 
 }
 
-Slice::JsVisitor::JsVisitor(Output& out, int warningLevel) : ParserVisitor(warningLevel), _out(out)
+Slice::JsVisitor::JsVisitor(Output& out) : _out(out)
 {
 }
 
@@ -329,10 +329,9 @@ Slice::JsVisitor::writeDocComment(const ContainedPtr& p, const string& deprecate
     _out << nl << " **/";
 }
 
-Slice::Gen::Gen(const string& base, const vector<string>& includePaths, const string& dir, int warningLevel) :
+Slice::Gen::Gen(const string& base, const vector<string>& includePaths, const string& dir) :
     _includePaths(includePaths),
-    _useStdout(false),
-    _warningLevel(warningLevel)
+    _useStdout(false)
 {
     _fileBase = base;
     string::size_type pos = base.find_last_of("/\\");
@@ -362,12 +361,10 @@ Slice::Gen::Gen(const string& base, const vector<string>& includePaths, const st
     printGeneratedHeader(_out, _fileBase + ".ice");
 }
 
-Slice::Gen::Gen(const string& base, const vector<string>& includePaths, const string& dir, ostream& out,
-                int warningLevel) :
+Slice::Gen::Gen(const string& base, const vector<string>& includePaths, const string& dir, ostream& out) :
     _out(out),
     _includePaths(includePaths),
-    _useStdout(true),
-    _warningLevel(warningLevel)
+    _useStdout(true)
 {
     _fileBase = base;
     string::size_type pos = base.find_last_of("/\\");
@@ -418,17 +415,17 @@ Slice::Gen::generate(const UnitPtr& p)
             _out.restoreIndent();
         }
     }
-    RequireVisitor requireVisitor(_out, _includePaths, icejs, es6module, _warningLevel);
+    RequireVisitor requireVisitor(_out, _includePaths, icejs, es6module);
     p->visit(&requireVisitor, false);
     vector<string> seenModules = requireVisitor.writeRequires(p);
 
-    TypesVisitor typesVisitor(_out, seenModules, icejs, _warningLevel);
+    TypesVisitor typesVisitor(_out, seenModules, icejs);
     p->visit(&typesVisitor, false);
 
     //
     // Export the top-level modules.
     //
-    ExportVisitor exportVisitor(_out, icejs, es6module, _warningLevel);
+    ExportVisitor exportVisitor(_out, icejs, es6module);
     p->visit(&exportVisitor, false);
 
     if(!es6module)
@@ -481,8 +478,8 @@ Slice::Gen::printHeader()
 }
 
 Slice::Gen::RequireVisitor::RequireVisitor(IceUtilInternal::Output& out, vector<string> includePaths,
-                                           bool icejs, bool es6modules, int warningLevel) :
-    JsVisitor(out, warningLevel),
+                                           bool icejs, bool es6modules) :
+    JsVisitor(out),
     _icejs(icejs),
     _es6modules(es6modules),
     _seenClass(false),
@@ -843,9 +840,8 @@ Slice::Gen::RequireVisitor::writeRequires(const UnitPtr& p)
     return seenModules;
 }
 
-Slice::Gen::TypesVisitor::TypesVisitor(IceUtilInternal::Output& out, vector<string> seenModules, bool icejs,
-                                       int warningLevel) :
-    JsVisitor(out, warningLevel),
+Slice::Gen::TypesVisitor::TypesVisitor(IceUtilInternal::Output& out, vector<string> seenModules, bool icejs) :
+    JsVisitor(out),
     _seenModules(seenModules),
     _icejs(icejs)
 {
@@ -1849,8 +1845,8 @@ Slice::Gen::TypesVisitor::encodeTypeForOperation(const TypePtr& type)
     return "???";
 }
 
-Slice::Gen::ExportVisitor::ExportVisitor(IceUtilInternal::Output& out, bool icejs, bool es6modules, int warningLevel) :
-    JsVisitor(out, warningLevel),
+Slice::Gen::ExportVisitor::ExportVisitor(IceUtilInternal::Output& out, bool icejs, bool es6modules) :
+    JsVisitor(out),
     _icejs(icejs),
     _es6modules(es6modules)
 {
diff --git a/cpp/src/slice2js/Gen.h b/cpp/src/slice2js/Gen.h
index dc3b65f18ba..8196ba1b48b 100644
--- a/cpp/src/slice2js/Gen.h
+++ b/cpp/src/slice2js/Gen.h
@@ -19,7 +19,7 @@ class JsVisitor : public JsGenerator, public ParserVisitor
 {
 public:
 
-    JsVisitor(::IceUtilInternal::Output&, int);
+    JsVisitor(::IceUtilInternal::Output&);
     virtual ~JsVisitor();
 
 protected:
@@ -44,14 +44,12 @@ public:
 
     Gen(const std::string&,
         const std::vector<std::string>&,
-        const std::string&,
-        int);
+        const std::string&);
 
     Gen(const std::string&,
         const std::vector<std::string>&,
         const std::string&,
-        std::ostream&,
-        int);
+        std::ostream&);
 
     ~Gen();
 
@@ -66,7 +64,6 @@ private:
     std::vector<std::string> _includePaths;
     std::string _fileBase;
     bool _useStdout;
-    int _warningLevel;
 
     void printHeader();
 
@@ -74,7 +71,7 @@ private:
     {
     public:
 
-        RequireVisitor(::IceUtilInternal::Output&, std::vector<std::string>, bool, bool, int);
+        RequireVisitor(::IceUtilInternal::Output&, std::vector<std::string>, bool, bool);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual bool visitStructStart(const StructPtr&);
@@ -106,7 +103,7 @@ private:
     {
     public:
 
-        TypesVisitor(::IceUtilInternal::Output&, std::vector< std::string>, bool, int);
+        TypesVisitor(::IceUtilInternal::Output&, std::vector< std::string>, bool);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -130,7 +127,7 @@ private:
     {
     public:
 
-        ExportVisitor(::IceUtilInternal::Output&, bool, bool, int);
+        ExportVisitor(::IceUtilInternal::Output&, bool, bool);
 
         virtual bool visitModuleStart(const ModulePtr&);
     private:
diff --git a/cpp/src/slice2js/Main.cpp b/cpp/src/slice2js/Main.cpp
index 03f17331e59..a73738fcee9 100644
--- a/cpp/src/slice2js/Main.cpp
+++ b/cpp/src/slice2js/Main.cpp
@@ -80,7 +80,6 @@ usage(const string& n)
         "                        deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore            Allow underscores in Slice identifiers\n"
         "                        deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn               Disable all warnings.\n"
         ;
 }
 
@@ -104,7 +103,6 @@ compile(const vector<string>& argv)
     opts.addOpt("d", "debug");
     opts.addOpt("", "ice");
     opts.addOpt("", "underscore");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
 
@@ -174,8 +172,6 @@ compile(const vector<string>& argv)
 
     bool underscore = opts.isSet("underscore");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -339,12 +335,12 @@ compile(const vector<string>& argv)
                     {
                         if(useStdout)
                         {
-                            Gen gen(icecpp->getBaseName(), includePaths, output, cout, warningLevel);
+                            Gen gen(icecpp->getBaseName(), includePaths, output, cout);
                             gen.generate(p);
                         }
                         else
                         {
-                            Gen gen(icecpp->getBaseName(), includePaths, output, warningLevel);
+                            Gen gen(icecpp->getBaseName(), includePaths, output);
                             gen.generate(p);
                         }
                     }
diff --git a/cpp/src/slice2objc/Gen.cpp b/cpp/src/slice2objc/Gen.cpp
index cc7b718c7e3..80b5609417e 100644
--- a/cpp/src/slice2objc/Gen.cpp
+++ b/cpp/src/slice2objc/Gen.cpp
@@ -12,9 +12,9 @@
 #include <limits>
 #include <sys/stat.h>
 #ifndef _WIN32
-#include <unistd.h>
+#  include <unistd.h>
 #else
-#include <direct.h>
+#  include <direct.h>
 #endif
 #include <IceUtil/Iterator.h>
 #include <IceUtil/UUID.h>
@@ -133,8 +133,7 @@ public:
 
 }
 
-Slice::ObjCVisitor::ObjCVisitor(Output& h, Output& m, const string& dllExport, int warningLevel) :
-    ParserVisitor(warningLevel), 
+Slice::ObjCVisitor::ObjCVisitor(Output& h, Output& m, const string& dllExport) :
     _H(h),
     _M(m),
     _dllExport(dllExport)
@@ -658,12 +657,11 @@ Slice::ObjCVisitor::getServerArgs(const OperationPtr& op) const
 }
 
 Slice::Gen::Gen(const string& name, const string& base, const string& include, const vector<string>& includePaths,
-                const string& dir, const string& dllExport, int warningLevel) :
+                const string& dir, const string& dllExport) :
     _base(base),
     _include(include),
     _includePaths(includePaths),
-    _dllExport(dllExport),
-    _warningLevel(warningLevel)
+    _dllExport(dllExport)
 {
     for(vector<string>::iterator p = _includePaths.begin(); p != _includePaths.end(); ++p)
     {
@@ -734,7 +732,7 @@ Slice::Gen::operator!() const
 void
 Slice::Gen::generate(const UnitPtr& p)
 {
-    ObjCGenerator::validateMetaData(p, _warningLevel);
+    ObjCGenerator::validateMetaData(p);
 
     //
     // Give precedence to --dll-export command-line option
@@ -834,25 +832,25 @@ Slice::Gen::generate(const UnitPtr& p)
     _M << nl << "#   pragma clang diagnostic ignored \"-Wshadow-ivar\"";
     _M << nl << "#endif";
 
-    UnitVisitor unitVisitor(_H, _M, _dllExport, _warningLevel);
+    UnitVisitor unitVisitor(_H, _M, _dllExport);
     p->visit(&unitVisitor, false);
 
-    ObjectDeclVisitor objectDeclVisitor(_H, _M, _dllExport, _warningLevel);
+    ObjectDeclVisitor objectDeclVisitor(_H, _M, _dllExport);
     p->visit(&objectDeclVisitor, false);
 
-    ProxyDeclVisitor proxyDeclVisitor(_H, _M, _dllExport, _warningLevel);
+    ProxyDeclVisitor proxyDeclVisitor(_H, _M, _dllExport);
     p->visit(&proxyDeclVisitor, false);
 
-    TypesVisitor typesVisitor(_H, _M, _dllExport, _warningLevel);
+    TypesVisitor typesVisitor(_H, _M, _dllExport);
     p->visit(&typesVisitor, false);
 
-    ProxyVisitor proxyVisitor(_H, _M, _dllExport, _warningLevel);
+    ProxyVisitor proxyVisitor(_H, _M, _dllExport);
     p->visit(&proxyVisitor, false);
 
-    DelegateMVisitor delegateMVisitor(_H, _M, _dllExport, _warningLevel);
+    DelegateMVisitor delegateMVisitor(_H, _M, _dllExport);
     p->visit(&delegateMVisitor, false);
 
-    HelperVisitor HelperVisitor(_H, _M, _dllExport, _warningLevel);
+    HelperVisitor HelperVisitor(_H, _M, _dllExport);
     p->visit(&HelperVisitor, false);
 }
 
@@ -881,8 +879,8 @@ Slice::Gen::printHeader(Output& o)
     o << "\n// Ice version " << ICE_STRING_VERSION;
 }
 
-Slice::Gen::UnitVisitor::UnitVisitor(Output& H, Output& M, const string& dllExport, int warningLevel) :
-    ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::UnitVisitor::UnitVisitor(Output& H, Output& M, const string& dllExport) :
+    ObjCVisitor(H, M, dllExport)
 {
 }
 
@@ -923,8 +921,8 @@ Slice::Gen::UnitVisitor::visitUnitEnd(const UnitPtr& unit)
     }
 }
 
-Slice::Gen::ObjectDeclVisitor::ObjectDeclVisitor(Output& H, Output& M, const string& dllExport, int warningLevel)
-    : ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::ObjectDeclVisitor::ObjectDeclVisitor(Output& H, Output& M, const string& dllExport)
+    : ObjCVisitor(H, M, dllExport)
 {
 }
 
@@ -944,8 +942,8 @@ Slice::Gen::ObjectDeclVisitor::visitClassDecl(const ClassDeclPtr& p)
     _H << nl << "@protocol " << fixName(p) << ";";
 }
 
-Slice::Gen::ProxyDeclVisitor::ProxyDeclVisitor(Output& H, Output& M, const string& dllExport, int warningLevel)
-    : ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::ProxyDeclVisitor::ProxyDeclVisitor(Output& H, Output& M, const string& dllExport)
+    : ObjCVisitor(H, M, dllExport)
 {
 }
 
@@ -959,8 +957,8 @@ Slice::Gen::ProxyDeclVisitor::visitClassDecl(const ClassDeclPtr& p)
     }
 }
 
-Slice::Gen::TypesVisitor::TypesVisitor(Output& H, Output& M, const string& dllExport, int warningLevel)
-    : ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::TypesVisitor::TypesVisitor(Output& H, Output& M, const string& dllExport)
+    : ObjCVisitor(H, M, dllExport)
 {
 }
 
@@ -2221,8 +2219,8 @@ Slice::Gen::TypesVisitor::writeMemberUnmarshal(const DataMemberList& dataMembers
     }
 }
 
-Slice::Gen::ProxyVisitor::ProxyVisitor(Output& H, Output& M, const string& dllExport, int warningLevel)
-    : ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::ProxyVisitor::ProxyVisitor(Output& H, Output& M, const string& dllExport)
+    : ObjCVisitor(H, M, dllExport)
 {
 }
 
@@ -2340,8 +2338,8 @@ Slice::Gen::ProxyVisitor::visitOperation(const OperationPtr& p)
     _H << " response" << responseExceptionSentDecl << deprecateSymbol << ";";
 }
 
-Slice::Gen::HelperVisitor::HelperVisitor(Output& H, Output& M, const string& dllExport, int warningLevel) :
-    ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::HelperVisitor::HelperVisitor(Output& H, Output& M, const string& dllExport) :
+    ObjCVisitor(H, M, dllExport)
 {
 }
 
@@ -2643,8 +2641,8 @@ Slice::Gen::HelperVisitor::visitStructStart(const StructPtr& p)
     return false;
 }
 
-Slice::Gen::DelegateMVisitor::DelegateMVisitor(Output& H, Output& M, const string& dllExport, int warningLevel)
-    : ObjCVisitor(H, M, dllExport, warningLevel)
+Slice::Gen::DelegateMVisitor::DelegateMVisitor(Output& H, Output& M, const string& dllExport)
+    : ObjCVisitor(H, M, dllExport)
 {
 }
 
diff --git a/cpp/src/slice2objc/Gen.h b/cpp/src/slice2objc/Gen.h
index 6b6c4c99b10..0c9ef639e7d 100644
--- a/cpp/src/slice2objc/Gen.h
+++ b/cpp/src/slice2objc/Gen.h
@@ -20,7 +20,7 @@ class ObjCVisitor : public ObjCGenerator, public ParserVisitor
 {
 public:
 
-    ObjCVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+    ObjCVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
     virtual ~ObjCVisitor();
 
 protected:
@@ -54,8 +54,7 @@ public:
         const std::string&,
         const std::vector<std::string>&,
         const std::string&,
-        const std::string&,
-        int);
+        const std::string&);
     ~Gen();
 
     bool operator!() const; // Returns true if there was a constructor error
@@ -72,7 +71,6 @@ private:
     std::string _include;
     std::vector<std::string> _includePaths;
     std::string _dllExport;
-    int _warningLevel;
 
     void printHeader(::IceUtilInternal::Output&);
 
@@ -80,7 +78,7 @@ private:
     {
     public:
 
-        UnitVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        UnitVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitUnitEnd(const UnitPtr&);
@@ -94,7 +92,7 @@ private:
     {
     public:
 
-        ObjectDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ObjectDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual void visitClassDecl(const ClassDeclPtr&);
     };
@@ -103,7 +101,7 @@ private:
     {
     public:
 
-        ProxyDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ProxyDeclVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual void visitClassDecl(const ClassDeclPtr&);
     };
@@ -112,7 +110,7 @@ private:
     {
     public:
 
-        TypesVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        TypesVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
@@ -158,7 +156,7 @@ private:
     {
     public:
 
-        ProxyVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        ProxyVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitClassDefEnd(const ClassDefPtr&);
@@ -169,7 +167,7 @@ private:
     {
     public:
 
-        HelperVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        HelperVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitClassDefStart(const ClassDefPtr&);
         virtual void visitEnum(const EnumPtr&);
@@ -182,7 +180,7 @@ private:
     {
     public:
 
-        DelegateMVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&, int);
+        DelegateMVisitor(::IceUtilInternal::Output&, ::IceUtilInternal::Output&, const std::string&);
 
         virtual bool visitModuleStart(const ModulePtr&);
         virtual void visitModuleEnd(const ModulePtr&);
diff --git a/cpp/src/slice2objc/Main.cpp b/cpp/src/slice2objc/Main.cpp
index 7877c072ca0..24ac096d92c 100644
--- a/cpp/src/slice2objc/Main.cpp
+++ b/cpp/src/slice2objc/Main.cpp
@@ -80,7 +80,6 @@ usage(const string& n)
         "                        deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore            Allow underscores in Slice identifiers\n"
         "                        deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn               Disable all warnings.\n"
         ;
     // Note: --case-sensitive is intentionally not shown here!
 }
@@ -106,7 +105,6 @@ compile(const vector<string>& argv)
     opts.addOpt("", "ice");
     opts.addOpt("", "underscore");
     opts.addOpt("", "case-sensitive");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
 
@@ -175,8 +173,6 @@ compile(const vector<string>& argv)
 
     bool underscore = opts.isSet("underscore");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": no input file" << endl;
@@ -289,8 +285,7 @@ compile(const vector<string>& argv)
                 {
                     try
                     {
-                        Gen gen(argv[0], icecpp->getBaseName(), include, includePaths, output, dllExport,
-                                warningLevel);
+                        Gen gen(argv[0], icecpp->getBaseName(), include, includePaths, output, dllExport);
                         if(!gen)
                         {
                             u->destroy();
diff --git a/cpp/src/slice2objc/ObjCUtil.cpp b/cpp/src/slice2objc/ObjCUtil.cpp
index ad2787308bc..e86290b8db3 100644
--- a/cpp/src/slice2objc/ObjCUtil.cpp
+++ b/cpp/src/slice2objc/ObjCUtil.cpp
@@ -1043,20 +1043,15 @@ Slice::ObjCGenerator::writeOptParamMarshalUnmarshalCode(Output &out, const TypeP
 }
 
 void
-Slice::ObjCGenerator::validateMetaData(const UnitPtr& u, int warningLevel)
+Slice::ObjCGenerator::validateMetaData(const UnitPtr& u)
 {
-    MetaDataVisitor visitor(warningLevel);
+    MetaDataVisitor visitor;
     u->visit(&visitor, true);
 }
 
 const string Slice::ObjCGenerator::MetaDataVisitor::_objcPrefix = "objc:";
 const string Slice::ObjCGenerator::MetaDataVisitor::_msg = "ignoring invalid metadata";
 
-Slice::ObjCGenerator::MetaDataVisitor::MetaDataVisitor(int warningLevel) :
-    ParserVisitor(warningLevel)
-{
-}
-
 bool
 Slice::ObjCGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
 {
@@ -1071,6 +1066,7 @@ Slice::ObjCGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
         DefinitionContextPtr dc = p->findDefinitionContext(file);
         assert(dc);
         StringList globalMetaData = dc->getMetaData();
+        bool emitWarnings = dc->suppressWarning("invalid-metadata");
         int headerDir = 0;
         int dllExport = 0;
         for(StringList::const_iterator r = globalMetaData.begin(); r != globalMetaData.end();)
@@ -1086,7 +1082,7 @@ Slice::ObjCGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                     headerDir++;
                     if(headerDir > 1)
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             ostringstream ostr;
                             ostr << "ignoring invalid global metadata `" << s
@@ -1102,7 +1098,7 @@ Slice::ObjCGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                     dllExport++;
                     if(dllExport > 1)
                     {
-                        if(warningLevel() > 0)
+                        if(emitWarnings)
                         {
                             ostringstream ostr;
                             ostr << "ignoring invalid global metadata `" << s
@@ -1113,7 +1109,7 @@ Slice::ObjCGenerator::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
                     }
                     continue;
                 }
-                if(warningLevel() > 0)
+                if(emitWarnings)
                 {
                     ostringstream ostr;
                     ostr << "ignoring invalid global metadata `" << s << "'";
diff --git a/cpp/src/slice2objc/ObjCUtil.h b/cpp/src/slice2objc/ObjCUtil.h
index 11e4cece024..cf5f1ee0b46 100644
--- a/cpp/src/slice2objc/ObjCUtil.h
+++ b/cpp/src/slice2objc/ObjCUtil.h
@@ -32,7 +32,7 @@ public:
     //
     // Validate all metadata in the unit with an "objc:" prefix.
     //
-    static void validateMetaData(const UnitPtr&, int);
+    static void validateMetaData(const UnitPtr&);
 
 protected:
     struct ModulePrefix
@@ -81,7 +81,6 @@ private:
     class MetaDataVisitor : public ParserVisitor
     {
     public:
-        MetaDataVisitor(int);
 
         virtual bool visitUnitStart(const UnitPtr&);
         virtual bool visitModuleStart(const ModulePtr&);
diff --git a/cpp/src/slice2php/Main.cpp b/cpp/src/slice2php/Main.cpp
index 787e83ac1b8..aace7d638ec 100644
--- a/cpp/src/slice2php/Main.cpp
+++ b/cpp/src/slice2php/Main.cpp
@@ -63,7 +63,7 @@ class CodeVisitor : public ParserVisitor
 {
 public:
 
-    CodeVisitor(IceUtilInternal::Output&, bool, int);
+    CodeVisitor(IceUtilInternal::Output&, bool);
 
     virtual void visitClassDecl(const ClassDeclPtr&);
     virtual bool visitClassDefStart(const ClassDefPtr&);
@@ -141,8 +141,7 @@ private:
 //
 // CodeVisitor implementation.
 //
-CodeVisitor::CodeVisitor(Output& out, bool ns, int warningLevel) :
-    ParserVisitor(warningLevel),
+CodeVisitor::CodeVisitor(Output& out, bool ns) :
     _out(out),
     _ns(ns)
 {
@@ -946,6 +945,11 @@ CodeVisitor::visitDictionary(const DictionaryPtr& p)
 
     TypePtr keyType = p->keyType();
     BuiltinPtr b = BuiltinPtr::dynamicCast(keyType);
+
+	const UnitPtr unit = p->unit();
+	const DefinitionContextPtr dc = unit->findDefinitionContext(p->file());
+	assert(dc);
+	bool emitWarnings = !dc->suppressWarning("invalid-metadata");
     if(b)
     {
         switch(b->kind())
@@ -964,7 +968,7 @@ CodeVisitor::visitDictionary(const DictionaryPtr& p)
         case Slice::Builtin::KindFloat:
         case Slice::Builtin::KindDouble:
         {
-            if(warningLevel() > 0)
+            if(emitWarnings)
             {
                 emitWarning(p->file(), p->line(), "dictionary key type not supported in PHP");
             }
@@ -980,7 +984,7 @@ CodeVisitor::visitDictionary(const DictionaryPtr& p)
     }
     else if(!EnumPtr::dynamicCast(keyType))
     {
-        if(warningLevel() > 0)
+        if(emitWarnings)
         {
             emitWarning(p->file(), p->line(), "dictionary key type not supported in PHP");
         }
@@ -1473,7 +1477,7 @@ CodeVisitor::collectExceptionMembers(const ExceptionPtr& p, MemberInfoList& allM
 }
 
 static void
-generate(const UnitPtr& un, bool all, bool checksum, bool ns, const vector<string>& includePaths, Output& out, int warningLevel)
+generate(const UnitPtr& un, bool all, bool checksum, bool ns, const vector<string>& includePaths, Output& out)
 {
     if(!all)
     {
@@ -1504,12 +1508,12 @@ generate(const UnitPtr& un, bool all, bool checksum, bool ns, const vector<strin
         }
     }
 
-    CodeVisitor codeVisitor(out, ns, warningLevel);
+    CodeVisitor codeVisitor(out, ns);
     un->visit(&codeVisitor, false);
 
     if(checksum)
     {
-        ChecksumMap checksums = createChecksums(un, warningLevel);
+        ChecksumMap checksums = createChecksums(un);
         if(!checksums.empty())
         {
             out << sp;
@@ -1620,7 +1624,6 @@ usage(const string& n)
         "                     deprecated: use instead [[\"ice-prefix\"]] metadata.\n"
         "--underscore         Allow underscores in Slice identifiers\n"
         "                     deprecated: use instead [[\"underscore\"]] metadata.\n"
-        "--no-warn            Disable all warnings.\n"
         ;
 }
 
@@ -1645,7 +1648,6 @@ compile(const vector<string>& argv)
     opts.addOpt("", "all");
     opts.addOpt("", "checksum");
     opts.addOpt("n", "no-namespace");
-    opts.addOpt("", "no-warn");
 
     bool validate = find(argv.begin(), argv.end(), "--validate") != argv.end();
 
@@ -1717,8 +1719,6 @@ compile(const vector<string>& argv)
 
     bool ns = !opts.isSet("no-namespace");
 
-    int warningLevel = opts.isSet("no-warn") ? 0 : 1;
-
     if(args.empty())
     {
         consoleErr << argv[0] << ": error: no input file" << endl;
@@ -1870,7 +1870,7 @@ compile(const vector<string>& argv)
                         //
                         // Generate the PHP mapping.
                         //
-                        generate(u, all, checksum, ns, includePaths, out, warningLevel);
+                        generate(u, all, checksum, ns, includePaths, out);
 
                         out << "?>\n";
                         out.close();